Feel free to ask Myles

[myles_rose]

Originally posted by morgwn:

Hi Myles,

 

A friend swears by Ruby EL34B-STR's in his Bogner 101b, so I'm thinking of going that route (need to get the amp rebiased though). I know Bogner runs his amps pretty hot though, and I have no idea about the reliability/durability of the Ruby tubes in a Bogner amp.

 

Sean at Bogner said "just get Svets" and I won't need to rebias, however, I've heard that the new Svets are junk...a local amp tech told me he used to love them, but the new ones he wouldn't think of puting in an amp. (he said the Ruby's are pretty good).

 

So I guess my dilemna is either tracking down an "older" quartet of Svets (where to find them I don't know), or trying something new and rebiasing the amp (experimentation time!). Durability is definitely key, as I don't want my amp blowing anything during a gig.

 

Any thoughts/experience would be helpful!!

 

Of course I would rather _not_ rebias my amp and save a little extra $$. Does switching to _any_ other tube that the Svetlana require rebias? (I'm almost under the impression that even replacing with Svets the amp _should_ need a rebias for optimum tone?)

 

Also, where does one get some of the "new" EH12ax7 tubes? (as I hear the latest ones are best?) And a matched phase inverter. Are there companies that pre-test/rank "preamp" tubes for gain and noise characteristics?

 

Thanks in advance,

Morgwn

Morgwn .....

 

Your friend, from my point of view, has good advice. There are many EL-34's on the market, but the new tooling Ruby EL-34BSTR may be the best of the 25 watt EL-34's around. It handles very high plate voltages, and unlike Chinese tubes of a year or less ago, they now have about 15% more power than the Russian tubes, rather than 20% less as in the past.

 

I did a review of this tube, with my test results posted on my personal website at

 

http://www.guitaramplifierblueprinting.com/el34.html

 

As far as "Svets", if you can find such a thing as an NOS Svetlana, with a date code prior to 2002, then you are in luck, as these are great tubes (not as linear or as close to a Siemens or Mullard in their curves as the Ruby Tubes offering though). Date codes of 2002-current, exhibit lower vacuum or plate material changes, which cause the tubes to have some issues I do not care for ... gassy, irregular curves, and a bigger change in performance after the first 20 or so hours of use.

 

Considering I also work for Groove Tubes, and we do not have the Ruby offering (by the way, nobody else does either for the most part, as the tooling for the EL-34BSTR was paid for by them), in the interest of great sounding amps, it is sad, but I have to defer your dollars on this tube sale to Ruby (Magic Parts).

 

You should rebias any time you change power tubes. BUT ... once you have EL-34BSTR Ruby's in there, then just ask for the same numbers as what come on the tubes from them when you get them the first time, and you will not have to re-bias in the future. Ruby's matching and consistency are top notch, and they do a great job of proper matching, unlike a lot of other folks.

 

Preamps tubes are all very different. If you look at the bottom of the section at http://www.guitaramplifierblueprinting.com/el34.html on my personal website, I go into this a lot.

 

The 12AX7EH (Groove Tubes 12AX7R3) is one of the two best to spec 12AX7's around today. It is only edged out by the Groove Tubes 12AX7C (or the Ruby tubes version of this tube, as GT and Ruby were the financial folks that did this tooling).

 

As far as pre-testing tubes, GT tests for low output, microphonics, and noise. They are one of the few that do that. The tubes are guaranteed to stay free of these defects for 6 months. Many tubes become microphonic in the first 30 days, and by then, most companies warranties have expired.

 

There are two ways of matching phase inverters ... a simple current or gain match, which is better than nothing, and a true dynamic curve tracer match. For a curve traced max, you will pay a LOT more for a tube, not just a buck or two.

 

A lot of this is covered in my 16 or so page tube document which is in progress but available if you write me at GT and ask for it.

[JonObi]

Hi Myles

 

Yep - that helped, as did all the other advice you've given me over the past week - Thank you very much.

 

I'm going to order from Doug Chandler, and I think i'm pretty sure i've got the right choice now. Anyway, this is what I think I'm going to go with;

 

- 12AX7R3

- 12AX7C9 (in v1)

- GTECC83S

- A matched quartet of GTE34LS (as recommended by Doug).

 

(p.s. - does it matter where the other 2 12AX7's go in the amp - i.e. - v2 or v3?)

 

Just to clarify - this will give me more gain and a warmer clean sound at higher volume's, then my amp gives me now?

 

Thanks again Myles, your help's always appreciated.

 

Cheers

 

JonObi

--------------------------------------------------------------------------------

 

JonObi ....

 

Wow ... this is getting long!

 

You will be happy with Doug Chandler, on a scale of 1-10, he is the typical 17

 

Your choice looks great.

 

On the E34Ls's .... get them in a 5 or 6 rating, as these are very VERY strong tubes, and in a higher rating than 6, they will almost never get to distort unless you are so loud that the authorities come after you.

 

It does not matter where the other 12AX7's go.

 

You will have more gain, more warmth, more touch sensitivity, more harmonic content (which will seem louder and allow you to drop the volume if desired), and a wider sound stage image of at least 10 degrees per side (walk around the amp while playing before tube changes and after and report back here with your findings) !!

Hi Myles,

 

Phew!! - It's taken over two months but it's done - re-tubed as above (my Marshall JCM 900 4100). Anyway, I said i'd let you know how it sounds, so i'll give it a try. Very impressed with the distortion, which is much smoother, + less harsh. The clean sound is alright - although not as impressed, the sound is very bright (with my strat) and tends to muddy a little with volume (esp. on neck pick-up) - sounds great for the blues/rock sort of sound - is there anyway of making the clean sound a little less bright + also less mudddy (or is this down to the GTE34LS's - they have a 5 rating).

 

The time delay is due to only knowing one amp tech, who kept realising each week he needed to order new resistors, parts etc... - probably won't go to him again!!

 

While I'm here Myles, I am setting up a guitar teaching business + need a couple of smallish practice amps - do you have any suggestions? Something betweeen the $200-$300 range wouild be perfect.

 

Anyway, sorry for the delay + thanks again for the help and advice. Keep up the good work.

 

Cheers

[fdeville99]

>Hey Myles,

>I have been playing for over 25 years and don't know squat about amps but I

>currently play in a blues band and play an am. standard strat with texas

>specials in it through a fend. hot rod deville 410. To get a clean sound

>that

>is at a manageable volume that doesn't sound weak and blatty I have been

>using a compressor. I am thinking of putting some of the ruby tubes in that

>change the 6L6s to the class a tubes with the adapters and also supposedly

>step down the wattage.

>Do you have any experience or feedback about this option or any other help?

>

>Thanks,

>Keith

[DanYmaL X]

Myles:

I asked a while ago (before NAMM) about the rumor I heard stating the Acoustic amp co. was back in business, and I have been unable to find anything to support that... so, I guess I am stuck working this out myself (scary thought.) Here's my problem, and although it's not a tube amp, I figured it is a question you should be able to answer for me...

My amp was working fine, but seemed to cut out almost imperceptibly (hah! spelled that right the first time!) But I could never find anything wrong with it.

But all of a sudden, for some reason, the only way I can get my amp to work is with a cable shorting(?) the FX loop (or by adding pedals to the loop.)

There does not appear to be anything wrong with the amp inside... no burns, shorts, (that I can see anyways, not being an electronics guru by any means.)

Is this common?

The amp is an Acoustic B-3 Collaborator head.

Any thoughts on this?

Thanks

DX

[JonObi]

JonObi .........

 

First off, you are more than welcome.

 

Second, this is a bit long and cofusing perhaps, but I will try to take this point by point.

 

Two months is not all that long, .... now that the time has passed I guess

 

The distortion is less harsh, because the first gain tube in the amp is smoother, and the output tubes are not pushed as hard in the high end as compared to their mids. This is why so many folks are into the E34L-S, which is about 15%-20% stronger than any other EL-34 tube. These are not the same as the JJ E34L, which some folks compare this tube to, as it comes from the same factory, as the plate structure is different.

 

To get the amp less clean and bright, first off, drop your bias so you have less current draw at idle. A BIG mistake a lot of folks make when biasing Marshalls, is to set the bias so the cross-over notch is gone, or almost gone. This is a big NO NO, as part of a Marshall's character, is some of the crossover notch distortion.

 

If you try the 12AX7C in V2, this may help tone down some of the brightness.

 

A 5 rating is great. If you had 7's, I tell you to drop to a 5.

 

Get a bias tool, bias probe, bias rite, bias king, or any of those. Your amp is a piece of cake to bias properly, and that is the route I would follow in the future. The first time or two you use it, it pays for itself. After that, you charge friends $25 or so to bias their amps. That makes you money, saves them money, and you are still 1/2 the cost or 1/4 the cost of a bias job here in Los Angeles. Fender amps are even easier than a Marshall.

 

Look at the Fender Blues Jr., sort of amps, or Peavey Classic 30's, or actually, there are a lot of great Crate small combos, that are Solid State, very reliable, cost effective, and save parents money in the long run as they have reverb and built in effects. If most kids buy a basic tube amp, next thing you know, the $299 amp is hooked up to a pedal board with $500 of effects in it, so these small combo sort of modeling amps are pretty great deals.

 

There are a lot of these that are pretty nice, most with a street price under $199. They are also lighter, more versitile, and do not need any tube changes over time, etc. They are good amps to see if a new player's interest will hold.

 

I also recommend the Line 6 Spyder 1x12 to a lot of parents looking for a first amp for their kids. It was the top of the pile a while back, but now, lots of folks have amps that are perhaps even less expensive and have even more features.

Thanks for the help Myles - I thought it would be a good idea learning to re-bias myself, while i was waiting (+ waiting) for someone else to do it for me!! Will probably look into it more now i think.

 

Thanks again Myles - i'll try switching the 12ax7c and see what happens. Cheers.

[myles_rose]

Originally posted by JonObi:

JonObi .........

 

First off, you are more than welcome.

 

Second, this is a bit long and cofusing perhaps, but I will try to take this point by point.

 

Two months is not all that long, .... now that the time has passed I guess

 

The distortion is less harsh, because the first gain tube in the amp is smoother, and the output tubes are not pushed as hard in the high end as compared to their mids. This is why so many folks are into the E34L-S, which is about 15%-20% stronger than any other EL-34 tube. These are not the same as the JJ E34L, which some folks compare this tube to, as it comes from the same factory, as the plate structure is different.

 

To get the amp less clean and bright, first off, drop your bias so you have less current draw at idle. A BIG mistake a lot of folks make when biasing Marshalls, is to set the bias so the cross-over notch is gone, or almost gone. This is a big NO NO, as part of a Marshall's character, is some of the crossover notch distortion.

 

If you try the 12AX7C in V2, this may help tone down some of the brightness.

 

A 5 rating is great. If you had 7's, I tell you to drop to a 5.

 

Get a bias tool, bias probe, bias rite, bias king, or any of those. Your amp is a piece of cake to bias properly, and that is the route I would follow in the future. The first time or two you use it, it pays for itself. After that, you charge friends $25 or so to bias their amps. That makes you money, saves them money, and you are still 1/2 the cost or 1/4 the cost of a bias job here in Los Angeles. Fender amps are even easier than a Marshall.

 

Look at the Fender Blues Jr., sort of amps, or Peavey Classic 30's, or actually, there are a lot of great Crate small combos, that are Solid State, very reliable, cost effective, and save parents money in the long run as they have reverb and built in effects. If most kids buy a basic tube amp, next thing you know, the $299 amp is hooked up to a pedal board with $500 of effects in it, so these small combo sort of modeling amps are pretty great deals.

 

There are a lot of these that are pretty nice, most with a street price under $199. They are also lighter, more versitile, and do not need any tube changes over time, etc. They are good amps to see if a new player's interest will hold.

 

I also recommend the Line 6 Spyder 1x12 to a lot of parents looking for a first amp for their kids. It was the top of the pile a while back, but now, lots of folks have amps that are perhaps even less expensive and have even more features.

Thanks for the help Myles - I thought it would be a good idea learning to re-bias myself, while i was waiting (+ waiting) for someone else to do it for me!! Will probably look into it more now i think.

 

Thanks again Myles - i'll try switching the 12ax7c and see what happens. Cheers.

Let me know what you find.

 

If you need help biasing, give me a call toll free at 1-800-459-5687 and I will step you through it over the phone, no matter whose bias adjustment tool you buy ... GT's or anybody elses.

[JonObi]

Let me know what you find.

 

If you need help biasing, give me a call toll free at 1-800-459-5687 and I will step you through it over the phone, no matter whose bias adjustment tool you buy ... GT's or anybody elses.

Cheers Myles - I'll keep you updated, but i'm based in England so it'll probably be through the forum!!

Are there any useful guides\books that take you through the principles of re-biasing?

 

Thanks again.

[myles_rose]

Originally posted by JonObi:

Let me know what you find.

 

If you need help biasing, give me a call toll free at 1-800-459-5687 and I will step you through it over the phone, no matter whose bias adjustment tool you buy ... GT's or anybody elses.

Cheers Myles - I'll keep you updated, but i'm based in England so it'll probably be through the forum!!

Are there any useful guides\books that take you through the principles of re-biasing?

 

Thanks again.

JonObi .........

 

The manual that comes with the GT version of the bias tool ( in the area of the GT website at http://www.groovetubes.com/groovetoys.cfm?Category_ID=30 ) comes with detailed instructions.

[fdeville99]

Myles,

Since I know squat about amp tubes I was wondering if you would suggest changing the 3 preamp tubes in my Hotrod dev. 410 and if so what would be your recommendation for those tubes for strickly blues playing and still trying to get a managable volume even after the switch to the EL84's with the rubytube adaptars. In this town in Oklahoma there is no guitar tech that knows more than how to sell an amp and maybe half way set up a guitar so you wisdom is invaluable here in the boonies.

Thanks,

Keith

[myles_rose]

Originally posted by fdeville99:

Myles,

Since I know squat about amp tubes I was wondering if you would suggest changing the 3 preamp tubes in my Hotrod dev. 410 and if so what would be your recommendation for those tubes for strickly blues playing and still trying to get a managable volume even after the switch to the EL84's with the rubytube adaptars. In this town in Oklahoma there is no guitar tech that knows more than how to sell an amp and maybe half way set up a guitar so you wisdom is invaluable here in the boonies.

Thanks,

Keith

fdeville99 ........ Keith,

 

Look for my post somewhere here on tube selection, follow the instructions, and get a 20 page document that will help a lot in this area.

[morgwn]

Myles,

I'd like to thank you for the Ruby EL34B-STR tube recommendation...those are VERY nice sounding tubes, and a LOT better than the Svets that were in there (much more even accross the freq. spectrum). They sound bigger, badder, and meaner, and with more bottom end and top end.

I still am not entirely in love with that amp (Bogner 101b), but now I know what tubes to buy! Thanks again!

-Morgwn

[myles_rose]

Originally posted by morgwn:

Myles,

I'd like to thank you for the Ruby EL34B-STR tube recommendation...those are VERY nice sounding tubes, and a LOT better than the Svets that were in there (much more even accross the freq. spectrum). They sound bigger, badder, and meaner, and with more bottom end and top end.

I still am not entirely in love with that amp (Bogner 101b), but now I know what tubes to buy! Thanks again!

-Morgwn

Morgwn ..........

 

You are more than welcome.

 

I wish I had a set of these Ruby's for a Victoria amp I am testing at the moment. I have Svets in there now, and know the nice aspects of the Rubys would make a nice difference.

 

Part of the reason for the difference is the plate material of the Rubys is better, and they also have a more complete vacuum over the current Svets.

[JonObi]

quote:

--------------------------------------------------------------------------------

JonObi .........

 

First off, you are more than welcome.

 

Second, this is a bit long and cofusing perhaps, but I will try to take this point by point.

 

Two months is not all that long, .... now that the time has passed I guess

 

The distortion is less harsh, because the first gain tube in the amp is smoother, and the output tubes are not pushed as hard in the high end as compared to their mids. This is why so many folks are into the E34L-S, which is about 15%-20% stronger than any other EL-34 tube. These are not the same as the JJ E34L, which some folks compare this tube to, as it comes from the same factory, as the plate structure is different.

 

To get the amp less clean and bright, first off, drop your bias so you have less current draw at idle. A BIG mistake a lot of folks make when biasing Marshalls, is to set the bias so the cross-over notch is gone, or almost gone. This is a big NO NO, as part of a Marshall's character, is some of the crossover notch distortion.

 

If you try the 12AX7C in V2, this may help tone down some of the brightness.

 

A 5 rating is great. If you had 7's, I tell you to drop to a 5.

 

Get a bias tool, bias probe, bias rite, bias king, or any of those. Your amp is a piece of cake to bias properly, and that is the route I would follow in the future. The first time or two you use it, it pays for itself. After that, you charge friends $25 or so to bias their amps. That makes you money, saves them money, and you are still 1/2 the cost or 1/4 the cost of a bias job here in Los Angeles. Fender amps are even easier than a Marshall.

 

Look at the Fender Blues Jr., sort of amps, or Peavey Classic 30's, or actually, there are a lot of great Crate small combos, that are Solid State, very reliable, cost effective, and save parents money in the long run as they have reverb and built in effects. If most kids buy a basic tube amp, next thing you know, the $299 amp is hooked up to a pedal board with $500 of effects in it, so these small combo sort of modeling amps are pretty great deals.

 

There are a lot of these that are pretty nice, most with a street price under $199. They are also lighter, more versitile, and do not need any tube changes over time, etc. They are good amps to see if a new player's interest will hold.

 

I also recommend the Line 6 Spyder 1x12 to a lot of parents looking for a first amp for their kids. It was the top of the pile a while back, but now, lots of folks have amps that are perhaps even less expensive and have even more features.

 

--------------------------------------------------------------------------------

 

Thanks for the help Myles - I thought it would be a good idea learning to re-bias myself, while i was waiting (+ waiting) for someone else to do it for me!! Will probably look into it more now i think.

 

Thanks again Myles - i'll try switching the 12ax7c and see what happens. Cheers.

--------------------------------------------------------------------------------

 

Let me know what you find.

 

If you need help biasing, give me a call toll free at 1-800-459-5687 and I will step you through it over the phone, no matter whose bias adjustment tool you buy ... GT's or anybody elses.

Hi Myles,

After my last message the amp developed a new problem - the (volume) kept cutting out, then returning, slowly fading out and then coming back, etc.........

I gave the tech a call + took the amp to him. Seems ok now, but i've only had it back a day. The clean channels much better. Do you have any idea what could have been causing this? (the volume droppping in and out)

 

Anyhow, while I was there I asked an assistant (not the tech - he'd gone) about dropping the bias so there's less current draw at idle and he said I'd need to give him a figure for the bias as it will mean changing components, not just a case of turning a dial. Could you please clarify for me - apologies for any ignorance!!

 

Thanks very much again Myles - Look forward to your reply.

 

JonObi

[JonObi]

JonObi.........

 

I cannot guess at this, I'd really need to see the amp. It can be anything from a bad preamp tube to a bad bias adjustment, where the tubes are running so hot, they heat up, then cool down then the amp is turned off.

 

A bias job is not all that difficult, even if components need to be changed as they may have to be on certain amps.

 

Which amp was this?

Hi Myles,

 

The amp is a Marshall JCM 900 4100 (100 Watt, dual reverb) head. I also use a Marshall Powerbrake at home.

 

Thanks

[pksdabombdj]

I just got my Dynaco Stereo-70 back from the shop, I have new Svet EL-34's in there and properly biased, but the "7199"s need replacing, they are weak. What would you suggest. I know these are no longer made. My amp guy suggested NOS JAN Phillips if I can find them. These cost twice as much as the Sovteks that are new product. What do you think. This is for home listening, maybe a few Hi-Fi DJ gigs (when I get my Klipsch La Scala's).

[myles_rose]

Originally posted by pksdabombdj:

I just got my Dynaco Stereo-70 back from the shop, I have new Svet EL-34's in there and properly biased, but the "7199"s need replacing, they are weak. What would you suggest. I know these are no longer made. My amp guy suggested NOS JAN Phillips if I can find them. These cost twice as much as the Sovteks that are new product. What do you think. This is for home listening, maybe a few Hi-Fi DJ gigs (when I get my Klipsch La Scala's).

pksdabombdj ...........

 

I would contact Mike at www.kcanostubes.com

[pksdabombdj]

Thanks for the link. Are there any substitute tubes(for the 7199) that might stay available for a while?

[JonObi]

JonObi .........

 

First off, you are more than welcome.

 

Second, this is a bit long and cofusing perhaps, but I will try to take this point by point.

 

Two months is not all that long, .... now that the time has passed I guess

 

The distortion is less harsh, because the first gain tube in the amp is smoother, and the output tubes are not pushed as hard in the high end as compared to their mids. This is why so many folks are into the E34L-S, which is about 15%-20% stronger than any other EL-34 tube. These are not the same as the JJ E34L, which some folks compare this tube to, as it comes from the same factory, as the plate structure is different.

 

To get the amp less clean and bright, first off, drop your bias so you have less current draw at idle. A BIG mistake a lot of folks make when biasing Marshalls, is to set the bias so the cross-over notch is gone, or almost gone. This is a big NO NO, as part of a Marshall's character, is some of the crossover notch distortion.

 

If you try the 12AX7C in V2, this may help tone down some of the brightness.

 

A 5 rating is great. If you had 7's, I tell you to drop to a 5.

 

Get a bias tool, bias probe, bias rite, bias king, or any of those. Your amp is a piece of cake to bias properly, and that is the route I would follow in the future. The first time or two you use it, it pays for itself. After that, you charge friends $25 or so to bias their amps. That makes you money, saves them money, and you are still 1/2 the cost or 1/4 the cost of a bias job here in Los Angeles. Fender amps are even easier than a Marshall.

 

Look at the Fender Blues Jr., sort of amps, or Peavey Classic 30's, or actually, there are a lot of great Crate small combos, that are Solid State, very reliable, cost effective, and save parents money in the long run as they have reverb and built in effects. If most kids buy a basic tube amp, next thing you know, the $299 amp is hooked up to a pedal board with $500 of effects in it, so these small combo sort of modeling amps are pretty great deals.

 

There are a lot of these that are pretty nice, most with a street price under $199. They are also lighter, more versitile, and do not need any tube changes over time, etc. They are good amps to see if a new player's interest will hold.

 

I also recommend the Line 6 Spyder 1x12 to a lot of parents looking for a first amp for their kids. It was the top of the pile a while back, but now, lots of folks have amps that are perhaps even less expensive and have even more features.

 

--------------------------------------------------------------------------------

 

Thanks for the help Myles - I thought it would be a good idea learning to re-bias myself, while i was waiting (+ waiting) for someone else to do it for me!! Will probably look into it more now i think.

 

Thanks again Myles - i'll try switching the 12ax7c and see what happens. Cheers.

--------------------------------------------------------------------------------

 

Let me know what you find.

 

If you need help biasing, give me a call toll free at 1-800-459-5687 and I will step you through it over the phone, no matter whose bias adjustment tool you buy ... GT's or anybody elses.

--------------------------------------------------------------------------------

 

Hi Myles,

After my last message the amp developed a new problem - the (volume) kept cutting out, then returning, slowly fading out and then coming back, etc.........

I gave the tech a call + took the amp to him. Seems ok now, but i've only had it back a day. The clean channels much better. Do you have any idea what could have been causing this? (the volume droppping in and out)

 

Anyhow, while I was there I asked an assistant (not the tech - he'd gone) about dropping the bias so there's less current draw at idle and he said I'd need to give him a figure for the bias as it will mean changing components, not just a case of turning a dial. Could you please clarify for me - apologies for any ignorance!!

 

Thanks very much again Myles - Look forward to your reply.

 

JonObi

--------------------------------------------------------------------------------

 

JonObi.........

 

I cannot guess at this, I'd really need to see the amp. It can be anything from a bad preamp tube to a bad bias adjustment, where the tubes are running so hot, they heat up, then cool down then the amp is turned off.

 

A bias job is not all that difficult, even if components need to be changed as they may have to be on certain amps.

 

Which amp was this?

Hi Myles

 

Doh! The fading sound problem is still there.

 

My amp is a Marshall JCM900 4100 (100 Watt Hi-gain dual reverb) from around '95-'96 - At home I use a Powerbrake, running the amp on the full (16ohms) power. Could the powerbrake have anything to do with this, or is it more likely a case of a bad bias?

I spoke to the tech again - he said he'd switched the 12ax7c into v2 and altered the bias, hence the improved clean channel, but the fading sound is still a problem - he thought he'd fixed it.

 

As the volume fades, the sound develops an unnatural, 'static' sort of sound.

 

Hope this helps you out a bit more

 

Cheers

[myles_rose]

Originally posted by pksdabombdj:

Thanks for the link. Are there any substitute tubes(for the 7199) that might stay available for a while?

pksdabombdj...

 

Sorry .... nope. This is also a problem with a compactron that is used in certain Fender amps too, such as the 6C10 and 6CX8.

[DanYmaL X]

I'm dredging this out of the depths... I just got around to cracking the chassis of my Danelectro Twin Fifteen, to look at the pots:

 

 

2.) I have no idea what this amp had for speakers... is there a way to tell by the tube setup?

 

There were a few configs, I would need to look at the serial number, pot date codes, and determine if they may have been Jense, CTS, Utah or Oxfords.

 

 

4.) How do I test it to make sure the components other than the tubes are ok?

 

The caps are probably dried out, but the first step is to check all the voltages and with a scope, look for 60 cycle noise that would be present if the power supply filter caps were gone. It is lack of use that kills capacitors faster than anything else.

 

My Dano Twin-15 Amp

The pots are almost all identical, and this is what is stamped on them:

Vibrato- Speed and Strength, and Channel 1&2- Low and Volume:

BB2917 1 MEG 137804

 

Channel 1&2- Highs:

BB2916 1 MEG 137741

 

There are no other markings on them, other than the Made in USA stamp on the shaft side of the pots...

 

The serial number is:

Series E model 215 SER 80858

 

And other than the label, FREED Transformer Co. Brooklyn NY and the number 24246 stencilled on it, the transformer is clean.

 

I'd really like to get this amp going... in your previous reply, you indicated that with these numbers you might be able to help me figure out what speakers were in this thing, for starters...

 

The tubes in it right now are all Raytheon, (the 2 12AX7's are unmarked though, and the 6AU6 just has some faded white paint...) The tubes are both Japanese and English.

At any rate, thats where I'm at with this thing. If you have any more you can add, I'd appreciate it, or if you can direct me to another source... I've checked with a few amp techs online, with no luck.

Thanks again

 

DX

[KARL FISHER]

Myles, I have a three year old Peavey Classic 100 tube head/amp. A few nights ago while playing, the sound started to vary occasionally from normal distortion, to a crisper, more tebly distortion. at other times, it might vary to a more muffled distortion. This has never happened before. At the time I had my guitar plugged into my Shure Guitarist diversity wireless, which I have had no problems with.

The next day, I pulled the tube covers, and fired the amp up, this tiime with just a traditional cable. the eight EL84? power tubes all appeared to have a normal glow, and all glowed the same. Even in a darkened room, the three 12AX7 preamp tubes were almost impossible to see a glow from.

 

I jammed with the amp again the next night, no wireless, and no wierd sounds from the amp. Any thoughts?

 

ALSO, wireless had a new battery, and the night of the wierd sounds, my guitar (new Explorer) also had a sensitivity to it. If I toughed metal, I heard a "click" in the amp, as if an electrical connection was made.

 

Tubes are Original. The amp gets used a max of about 6 hours a week. Some weeks much less time.

By the way, I play mostly SKYNYRD stuff, so if I do need any tubes, can you suggest a tube type that might give me more of the "Twangy squeel" I get from the sting/pick for a lot of my leads???

 

Thanks, Karl (Skynfan)

 

Karl

[myles_rose]

Originally posted by KARL FISHER:

Myles, I have a three year old Peavey Classic 100 tube head/amp. A few nights ago while playing, the sound started to vary occasionally from normal distortion, to a crisper, more tebly distortion. at other times, it might vary to a more muffled distortion. This has never happened before. At the time I had my guitar plugged into my Shure Guitarist diversity wireless, which I have had no problems with.

The next day, I pulled the tube covers, and fired the amp up, this tiime with just a traditional cable. the eight EL84? power tubes all appeared to have a normal glow, and all glowed the same. Even in a darkened room, the three 12AX7 preamp tubes were almost impossible to see a glow from.

 

I jammed with the amp again the next night, no wireless, and no wierd sounds from the amp. Any thoughts?

 

ALSO, wireless had a new battery, and the night of the wierd sounds, my guitar (new Explorer) also had a sensitivity to it. If I toughed metal, I heard a "click" in the amp, as if an electrical connection was made.

 

Tubes are Original. The amp gets used a max of about 6 hours a week. Some weeks much less time.

By the way, I play mostly SKYNYRD stuff, so if I do need any tubes, can you suggest a tube type that might give me more of the "Twangy squeel" I get from the sting/pick for a lot of my leads???

 

Thanks, Karl (Skynfan)

 

Karl

Karl,

 

I'd need to see the amp. Some 12AX7s will have no glow as the heater is enclosed.

 

Wireless can also have some problem aspects.

 

The best way to discuss this is if you just call me at GT ( 1-800-459-5687 ) and we can talk a bit. If it is today, Monday, wait until after about 1pm to call.

[FourT6and2]

Myles, I know your a tube man but i need some advice about cabs, and well you know your stuff.

 

I have a Dual Rectifier and so far the only cabs i have found that i can afford and that seem halfway decent are Mesa Boogie 2x12 rectifier with vintage 30's and a closed back rated at 120-140 watts RMS. A Madison 4x12 rated at 340 watts with madison symphony speakers(107dB, 1.75" voice coil and 50 oz. magnets). Genz Benz G-Flex (ported with vintage 30 clones--2x12). and last but not least Avatar 4x12 with a combo of vintage 30's and G12H's.

 

I play a lot of high gain riffage and modern/hard rock....but a lot of clean as well. My main concern is break up at high volumes...i dont want a flabby speaker cab...who does? My mesa puts out a lot of bass and i need a cab that handles it.

 

What are your suggestions....i have a tight budget of no more than $500 or so....maybe not even.

 

Thanks

[myles_rose]

Originally posted by FourT6and2:

Myles, I know your a tube man but i need some advice about cabs, and well you know your stuff.

 

I have a Dual Rectifier and so far the only cabs i have found that i can afford and that seem halfway decent are Mesa Boogie 2x12 rectifier with vintage 30's and a closed back rated at 120-140 watts RMS. A Madison 4x12 rated at 340 watts with madison symphony speakers(107dB, 1.75" voice coil and 50 oz. magnets). Genz Benz G-Flex (ported with vintage 30 clones--2x12). and last but not least Avatar 4x12 with a combo of vintage 30's and G12H's.

 

I play a lot of high gain riffage and modern/hard rock....but a lot of clean as well. My main concern is break up at high volumes...i dont want a flabby speaker cab...who does? My mesa puts out a lot of bass and i need a cab that handles it.

 

What are your suggestions....i have a tight budget of no more than $500 or so....maybe not even.

 

Thanks

FourT6and2 ............

 

Your best bet in your price range may be ebay. On new stuff, the Marshall AVT 4x12 cabs are in that price range and are pretty nice for their price. They handle high wattage, and are a bit more compact than a Marshall 1960 cab.

 

The best 2x12 cab around that competes really well with 4x12 cabs, is the THD cabinet. These are about $700-$800 retail, I am not sure, but perhaps somebody may discount.

[DanYmaL X]

Myles:

 

Are 'Substi-Tubes' the way to go to replace a 6SN7GT? I saw them on the Groove Tubes website. At $40.00 a pop, am I better off trying to find a replacement 6SN7 or going with the 12AX7 adapter?

 

DX

[myles_rose]

Originally posted by danymal_x:

Myles:

 

Are 'Substi-Tubes' the way to go to replace a 6SN7GT? I saw them on the Groove Tubes website. At $40.00 a pop, am I better off trying to find a replacement 6SN7 or going with the 12AX7 adapter?

 

DX

DX ............

 

Lots of folks swear by them ....

[johnny5]

Myles,

 

below was posted in the "which tubes should I use" section but thought it might get seen here.

 

After reading your article "which tubes should I use", I am much better informed yet still feel I am missing something. Maybe there are others with me here, so let me try to explain;

 

I am trying to understand the differences in the 6L6 tubes (or just power tubes in general). I play rocky blues and hard rock (I know the two guitar sounds are different) and I am wondering what the best tube is for me. I have some KT66HP's right now and for the blues side of playing, these tubes kick butt. However, when I kick up the preamp gain (or kick the OD pedal) for a hard rock sound, the lows just don't seem tight enough. There also seems to be more low mids than high mids.

 

My dilemma is that I read “easily pushed into distortion” (6L6CB), I think that would be great for hard rock, but now I am thinking twice, three times and am a bit confused.

Then I read “#3 rating for earlier breakup” and I feel that would be good for rock too so by the time I have the amp at 7, the power tubes are saturated and things are compressed and not falling in and out of power tube distortion. Yet you say the heavy rocker prefer the high GT rated tubes for clean headroom. Why would you want clean headroom for heavy rock?

 

Say in a modern Mesa or Marshall ,would the sound of those amps be more characterized by pre-amp gain or power tube gain? For instance, the classic Marshall metal sound probably has very high gain in the preamp and lots of headroom in the power amp? Or is it visa-versa?

 

I think there are other folks out there who do not completely understand as I do and some of the terminology used can be misleading as far as what we read and what it represents sonically. Could you help us poor fools out?

 

Thank you,

John

[saje7]

'84 JCM 800 2203

 

Power switch light burned out of course, the old switch has a black wire (ground?) running from the voltage selector in addition to the other four conducts.

The new switch doesn't have the fifth pole for the black wire, any thoughts? Much appreciated...

--------------------------------------------------------------------------------

[myles_rose]

Originally posted by johnny5:

Myles,

 

below was posted in the "which tubes should I use" section but thought it might get seen here.

 

After reading your article "which tubes should I use", I am much better informed yet still feel I am missing something. Maybe there are others with me here, so let me try to explain;

 

I am trying to understand the differences in the 6L6 tubes (or just power tubes in general). I play rocky blues and hard rock (I know the two guitar sounds are different) and I am wondering what the best tube is for me. I have some KT66HP's right now and for the blues side of playing, these tubes kick butt. However, when I kick up the preamp gain (or kick the OD pedal) for a hard rock sound, the lows just don't seem tight enough. There also seems to be more low mids than high mids.

 

My dilemma is that I read “easily pushed into distortion” (6L6CB), I think that would be great for hard rock, but now I am thinking twice, three times and am a bit confused.

Then I read “#3 rating for earlier breakup” and I feel that would be good for rock too so by the time I have the amp at 7, the power tubes are saturated and things are compressed and not falling in and out of power tube distortion. Yet you say the heavy rocker prefer the high GT rated tubes for clean headroom. Why would you want clean headroom for heavy rock?

 

Say in a modern Mesa or Marshall ,would the sound of those amps be more characterized by pre-amp gain or power tube gain? For instance, the classic Marshall metal sound probably has very high gain in the preamp and lots of headroom in the power amp? Or is it visa-versa?

 

I think there are other folks out there who do not completely understand as I do and some of the terminology used can be misleading as far as what we read and what it represents sonically. Could you help us poor fools out?

 

Thank you,

John

..............

 

John,

 

6L6's, or any power tubes, all have different characteristics and tone. Their construction is different, simple or complex plate structures, high or lower vacuum, and other factors.

 

For blues, for my tastes, I like KT-66HP's with their more linear mids, or the 6L6CB coke bottles, with their softer vacuum and lower output. I prefer 3's to 7's as an example also. In an amp like a Super Reverb, a "3" will start to break at 3 or so on the volume control, where a "7" as an example will stay clean to an amp setting of say 4 1/2 or even 5. Tubes with lower number ratings sound the same, but do so at a lower volume level, so they are great for recording or smaller venues. They also have a wider range of touch sensitivity and dynamics.

 

Folks that like 8,9,10's are folks that want as much clean headroom as possible, generally folks that get their tone and sound from pedals and effects, rather than the output section of the amp. That is pretty popular today.

 

My personal favorite range is 4-6, as these are the most versitile, and the range that the amps were designed around to be expected in the first place. In a fixed bias amp such as a Mesa amp, you can use any GT 4-6, as this is the same range as Mesa uses in their amps and supplies as their replacement tubes.

 

In a modern Mesa or Marshall, there is a lot more change to be heard from preamp tubes also, so this is a big factor.

[myles_rose]

Originally posted by saje7:

'84 JCM 800 2203

 

Power switch light burned out of course, the old switch has a black wire (ground?) running from the voltage selector in addition to the other four conducts.

The new switch doesn't have the fifth pole for the black wire, any thoughts? Much appreciated...

--------------------------------------------------------------------------------

I would need to see this amp, as it does not sound stock, or sounds as if it had a ground problem and somebody tried to fix it in some strange way.