Feel free to ask Myles

[Blue Note]

Myles,

 

I got a couple more questions. I started looking at my Princeton Reverb last night and noticed the phase inverter was a 12AX7 instead of a 12AT7.

I then went to schematic and it says the phase inverter is only using half of the 12AX7. So my question, is a matched phase inverter important in this design? And if so would a 12AT7 be alright? I have some matched AT7's but no AX7's.

 

Also I asked a couple of questions about my Champ, the sine wave and some Sylvania tubes in a earlier post. I know you have many questions to answer and probably just missed it.

 

Hope I'm not driving you crazy with so many questions. The good thing is just a couple more amps then I'll have to buy some more to work on. Which will probably take a while.

 

Thanks again for your help.

[myles_rose]

Originally posted by milobender:

Brian

Brian ....

 

Your TBR1M, you will love it ....

 

I know a bit about these:

 

******Picture of TBR-1M*******

 

Thanks Myles, That's a picture of my new baby! I love this amp. It definately wants tweaking, but unlike alot of other posts I've read, I like to tweak... it can change right along with my ecclectic-gordian-knot moods.

 

I should receive a Bias Rite by the first of next week; and I'm going to give you a call as you offered.

 

Thanks again for all the great forums/chats/threads... It's really great information, and tremendously generous of you to provide so much time and energy.

 

Alas, you've (nearly single handedly) turned me into the beast the corporate world is hating at the moment... an employee spending the better part of the work day reading totally non work oriented info on the web!!! Great Stuff.

 

Brian

 

Oh, and my wife informed me over lunch that she's a GASS... a Gear Acquisition Syndrom Survivor![/QB]

 

milobender (Brian) ....

 

You are more than welcome. I think you will love the amp. They are incredibly versitile. Play with the Pcomp a lot ... it is magic.

 

Wehn you get your bias rite, get the amp open, and give me a call. I will step you through it over the phone. The toll free number here is 1-800-459-5687.

 

I used to do the same things as you when I was in that corporate environment (VP of engineering for Infonet ( www.infonet.com ) for a LOT of years as my "day job".

[myles_rose]

Originally posted by TieDyedDevil:

Originally posted by myles111:

Originally posted by TieDyedDevil:

Myles --

 

From what I've read about Mesa/Boogie, the "bins" of their color-coding scheme for output tube are pretty narrow and their amps are biased conservatively for longer tube life. Is it reasonable for me to substitute tubes having different color codes in order to experiment with the effects of different kinds of tubes (as supported by the amp) and running tubes hotter or colder than stock? What are the risks in trying this without bothering to measure plate dissipation? Is M/B's spread from hottest to coldest tubes wide enough to cause problems in their own amps?

TieDyedDevil .......

 

Even with Mesa's tubes, most of their amps are overbiased and run too cool for my personal tastes. The scale from Mesa to GT is:

 

Mesa vs Groove Tubes scale

Red 4

Yellow 4

Green 5

Gray 5

Blue 6

White 6

 

If when using a #6, if I am still at less than 55% or so ID, I just go to a #7 ... outside of Mesa's range, but nicer for the tone.

 

Within Mesa's range, you will not see problems and have very long tube life.

 

If you want to stray from this range, you need to check ID.

Hmmmm, that's what I suspected. Which leaves me a bit confused about M/B's guidance to replace tubes only with the same bias.

 

I wonder whether they're trying to ensure that the amp sounds "the same" as when it left the factory, or just trying to avoid a run on their stocks of hotter tubes.

TieDyedDevil .........

 

The reason Mesa does this, or at least one reason, is for reliability and consistency. I have seen so many improperly biased amps, that I lost count over two decades ago! There are great fixed bias amps (non-adjustable), such as Hiwatt, and even the 59 tweed bassman. My own personal Mesa amps are stock .... I have not even installed an adjustable bias pot in them (ten minutes and less than $1.00 for me). They work great as they come from the factory, it is just a matter of selecting tubes that get the idle dissapation where I want it to be, and there it stays.

 

Mesa amps have long tube life with their own tubes, which are in a narrower range to work great with their thinking. I prefer something outside of their range, so it boils down to personal taste and preference for the most part. Mesa tubes are very nicely matched, and also something of a bargain with darn nice pricing too.

[myles_rose]

Originally posted by Curly Dan:

Myles:

a belated thanks to you for looking at my Bassman last weekend at Norm's ...

I got home, rebiased, and switched the Sovtek 12AX7 with the 12AX7C you gave me, and whaddya know, it knocked down a lot of the the background noise, and sounded a lot smoother to me ...

I also got some KT66's (GT #2's) to try, but they're so !$%$^%& BIG they don't fit. I might just pull the chassis, though, just to give 'em a try.

 

I followed your link to Victoria's site and read Mark's comments regarding FRED's. Do you have any experience or opinion on using these in the rectifier section? They sound intriguing.

 

Thanks again,

Curly Dan

Curly Dan ...........

 

You are more than welcome. It is always great to meet folks face to face from this forum. I usually have a few free items for folks from this

forum when I meet them.

 

The 12AX7C has more gain and output than the stock sovtek 12AX7WA, and is much more linear and smooth. A Sovtek 12AX7WA is quiet though in a lot of amps, as it is so low on gain and output, but also low on tone in a manner of speaking.

 

The KT-66's are too tall for a lot of amps. Even in my JTM-45, which had these as stock, it is a tight fit, where the chassis has to be pulled to change the tubes, and then slid back into the box.

 

The 6L6GE's are even more amazing in your amp in a lot of ways.

 

FRED's (fast recovery expitial diodes), probably spelled that very wrong), are interesting. I am still trying to figure them out from a taste point of view. For a tight sound I like regular 4007 type diodes, and for a tube rectified feel I like real tube rectifiers, so I am still trying to make a case for them for my own views I guess.

 

It was great to meet you and the other folks that came in that day.

[myles_rose]

Originally posted by Blue Note:

Myles,

 

I got a couple more questions. I started looking at my Princeton Reverb last night and noticed the phase inverter was a 12AX7 instead of a 12AT7.

I then went to schematic and it says the phase inverter is only using half of the 12AX7. So my question, is a matched phase inverter important in this design? And if so would a 12AT7 be alright? I have some matched AT7's but no AX7's.

 

Also I asked a couple of questions about my Champ, the sine wave and some Sylvania tubes in a earlier post. I know you have many questions to answer and probably just missed it.

 

Hope I'm not driving you crazy with so many questions. The good thing is just a couple more amps then I'll have to buy some more to work on. Which will probably take a while.

 

Thanks again for your help.

Blue Note .........

 

In your amp, a matched phase inverter would not be needed. This is also true of most champs and fender tweed amps such as the deluxe and tweed super.

 

Keep the 12AX7.

 

I thought I answered your sine wave questions etc.

[johnny5]

MYLES,

i have got the reverend hellhound and have been messing with it since i got it. partially cuz i love to tweek things and partially to find the tone. i out some KT-66's in it and it's really nice with the cleans and just breaking uo blues sound. problem is, my band plays rock, mostly distorted guitar rock. my amp does it but kinda doesn't like it if you know what i mean.

 

i am thinking of doing the mod to convert to EL34's to get more of a JCM800 sound. i read that when done, you can still use 6L6's (just re-adjust bias).

 

1) will this mod make the overall amp sound darker (less treble)? even with 6L6's in?

 

2) or should i just try some low rated (maybe #3 GT) 6L6S's?

 

thanks,

john

[soulman]

Miles,

I traded in my Fender Hot Rod DeVille 410 and got a Hot Rod Deluxe to save my back (but am still wondering if I won't kick myself later). Now I need to do some work on it to get it up to par. How do you think the KT66HP's would do in this amp? I like a tighter bass and crisp highs. I am also considering putting a 12AX7XC in V1 and possibly changing the speaker to a Celestion Vintage 30 or possibly a Jensen P12N. If you could give me some hints on all those things I would be grateful. Thank you.

[ManInTheBox]

Hey Myles, what is the difference between a 6L6GC STR 454 and a 6L6GC 420? What do those STR numbers mean?

[Blue Note]

Myles,

 

Thanks for the info on the 12AX7 inverter, I haven't had a chance to work on the Princeton yet but since I don't need a matched 12AX7 I have every thing I need and hope to get a chance this week.

 

Just thought of a question over the weekend, in between sets I have always turned my standby switch to off, but the other guitar player in the band always leaves his on. We normaly take a 20-30 minute break and I was wondering if maybe I was causing more harm than good by doing this. Also how much time before the gig should you turn your amp on to let the tubes warm up.

 

Just want to make my amp and tubes last as long as possible.

 

Thanks for your time.

[ManInTheBox]

I can't remember if I asked this or not. But Myles, when would you say is a good time to leave an amp alone, and get another one. From what I have been reading, the differences in tubes should allow a person to get just about any amp to do whatever they want. Is there some limitation that I am missing here?

[myles_rose]

Originally posted by johnny5:

MYLES,

i have got the reverend hellhound and have been messing with it since i got it. partially cuz i love to tweek things and partially to find the tone. i out some KT-66's in it and it's really nice with the cleans and just breaking uo blues sound. problem is, my band plays rock, mostly distorted guitar rock. my amp does it but kinda doesn't like it if you know what i mean.

 

i am thinking of doing the mod to convert to EL34's to get more of a JCM800 sound. i read that when done, you can still use 6L6's (just re-adjust bias).

 

1) will this mod make the overall amp sound darker (less treble)? even with 6L6's in?

 

2) or should i just try some low rated (maybe #3 GT) 6L6S's?

 

thanks,

john

John (johnny5) .........

 

I am not sure what you meant in the first paragraph.

 

You can just make sure the screen resistors are 1k 5 watters, and then you can go from 6L6's to EL-34's for the most part, but like most compromise amps of today that can use both, the output transformer will be a compromise in impedance matching.

 

Your amp will not sound like a JCM 800 in any way though, as the front ends of these amps are very different. The output tubes are the smallest part of this sound actually. The power transformer will also be under more load, as the heater current of these two tubes is different.

 

If you want the sound of a JCM 800, then buy one on ebay or something maybe.

 

I'd try some 6L6S's first. A lot less expensive.

[myles_rose]

Originally posted by soulman:

Miles,

I traded in my Fender Hot Rod DeVille 410 and got a Hot Rod Deluxe to save my back (but am still wondering if I won't kick myself later). Now I need to do some work on it to get it up to par. How do you think the KT66HP's would do in this amp? I like a tighter bass and crisp highs. I am also considering putting a 12AX7XC in V1 and possibly changing the speaker to a Celestion Vintage 30 or possibly a Jensen P12N. If you could give me some hints on all those things I would be grateful. Thank you.

soulman ..........

 

I like the 1x12 and 2x12 Hot Rods more than the 4x10, for the weight and size aspects myself, and they all sound nice, so I don't see you kicking yourself in the future.

 

KT-66HP's have stronger and more linear mids, but in some amps, not the highs of say a 6L6S or 6L6GE. It boils down to user preference and taste.

 

If you want lots of sparkling highs, go to a 7025 in V1.

 

The best of the 7025's are NOS, and not that pricy. The ones I like mostly are from Mike at KCA ... www.kcanostubes.com and currently from his stock I'd go for ............

 

NOS RCA 12AX7/As--------------------------------------------------------$ 50

Original boxes. Great original equipment tubes for Fenders and other guitar amps. A few ca. 1960 gray/long plates still in stock.

(these are great and actually cheap, when you learn that these last at least five times longer and any new tubes made today)

 

NOS RCA 7025s--------------------------------------------------------------Sold Out

Only 2 in stock. Very rare. Stock equipment for V1 and V2 in Fender blackface 2 channel amps.

(........... these are great when he gets more)

 

NOS GE 12AX7A------------------------------------------------------------$ 32 each

Commercial version with white lettering. 1960s variety and a few ca 1960 long/wide plate version. Great guitar amp and audiophile tube. Very sweet sounding with a smooth top end. Very low in microphonics and noise.

Here's one of my favorite quotes: "One last question, do you have any of the NOS GE 12AX7A's with the white lettering? I got one of these out of an old Silver face Pro Reverb and tried it in V1 in my HotRod Deluxe and almost had to change my underwear it sounded so good!!! Unfortunately I had to put it back in the Pro reverb...sounds great in there to!!! Thanks Randy W"

 

NOS JAN Raytheon 12AX7s (Grade I)-----------------------------------$ 25 Each

Long/wide/grey plate version in original military boxes with 1962 date codes. Great guitar tone

similar to GE long/wide plate 12AX7s. Tested and screened for low microphonics.

 

NOS JAN Raytheon 12AX7s (Grade II)----------------------------------$ 20 each

These have slightly higher microphonics than Grade I's. May not be appropriate for use in V1

or V2 in Fender 2 channel COMBO amps or in high gain amps. Work fine as V4 or V5 in

Fender 2 channel reverb amps or phase inverters in amps that call for 12AX7s in the PI position.

 

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

 

Any of those are great....

 

Celestion vs Jensen is also a personal issue, but in your amp I love the Jensen C12N more than the P12N for some reason. Others may disagree with me on this, and they are valid too.

[myles_rose]

Originally posted by tundrkys:

Hey Myles, what is the difference between a 6L6GC STR 454 and a 6L6GC 420? What do those STR numbers mean?

tundrkys...........

 

STR used to stand for Special Tube Request, back in the days when folks like Fender went to Sylvania, and asked for a 6L6 that was to be mounted upside down, close to a speaker. The STR-387 by Tom Rubio was the result.

 

The numbers you mention are Mesa tubes, and are not true STR tubes.

 

The Mesa STR-454 is the Svetlana tube

 

The Mesa STR-420 is a Chinese tube.

 

Mesa tubes are for the most part, pretty nice bargains, and nicely tested and graded.

[myles_rose]

Originally posted by Blue Note:

Myles,

 

Thanks for the info on the 12AX7 inverter, I haven't had a chance to work on the Princeton yet but since I don't need a matched 12AX7 I have every thing I need and hope to get a chance this week.

 

Just thought of a question over the weekend, in between sets I have always turned my standby switch to off, but the other guitar player in the band always leaves his on. We normaly take a 20-30 minute break and I was wondering if maybe I was causing more harm than good by doing this. Also how much time before the gig should you turn your amp on to let the tubes warm up.

 

Just want to make my amp and tubes last as long as possible.

 

Thanks for your time.

Blue Note .........

 

You are more than welcome.

 

When you are going to stop playing for a few minutes or more, I put the amp in standby.

[myles_rose]

Originally posted by tundrkys:

I can't remember if I asked this or not. But Myles, when would you say is a good time to leave an amp alone, and get another one. From what I have been reading, the differences in tubes should allow a person to get just about any amp to do whatever they want. Is there some limitation that I am missing here?

tundrkys............

 

There is much more than just tubes. There is the entire design and topology. You can change tubes all day in a Fender to make it sound like a Marshall, and it will never happen ... and visa versa.....

 

I guess you have not read much on my personal website

 

see:

 

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

[ManInTheBox]

Ok, so maybe I overexagerrated ( and I don't appreciate the slap on the hands either) lol.

But what I meant to ask, was how do you know when you reached the end with your blueprinting. I mean if I like the tone I am getting, but think I can get a little more sweetness, I could be working on an amp for a lifetime, and never be happy.

I guess it is up to me to decide when enough is enough hugh?

anyway, thanks for all your time.

[myles_rose]

Originally posted by tundrkys:

Ok, so maybe I overexagerrated ( and I don't appreciate the slap on the hands either) lol.

But what I meant to ask, was how do you know when you reached the end with your blueprinting. I mean if I like the tone I am getting, but think I can get a little more sweetness, I could be working on an amp for a lifetime, and never be happy.

I guess it is up to me to decide when enough is enough hugh?

anyway, thanks for all your time.

tundrkys ........

 

An amp is finished in less than a day usually. When it sounds proper, sort of meaning, as a great example of what the best of a particular model sounds like, and has the proper touch and feel, then we move on. If the future, if a player wants more or less of some characteristic, within the design possibilities of that particular amp, this can be done with science, rather than luck, as each aspect of any blueprinted amp is recorded and documented.

 

If you want to turn your Crate combo into a Mesa Mark IV, there will be no need to blueprint, I will tell you to buy a different amp more suited to that sound.

 

We just make something the best it can be for what it is.

[TieDyedDevil]

Myles --

 

I have a line on two different Mesa/Boogie Mark IIIs - an early 90's simulclass combo and a late 80's Coliseum 300 head. Both have reverb and EQ. The combo has an EVM-12L speaker and the head would be paired up with my 80's 2x12 vertical half-back cab with a Celestion 90 in the open top and an EVM-12L in the ported bottom.

 

I'm trying to decide which one to buy. Do you have any experience with these? Any insights? I'm inclined to go with the smaller amp for the sake of size, but willing to consider the more powerful head if there's a compelling sonic difference. (BTW, I can't audition the Coliseum - I'd be having it shipped to me.)

[myles_rose]

Originally posted by TieDyedDevil:

Myles --

 

I have a line on two different Mesa/Boogie Mark IIIs - an early 90's simulclass combo and a late 80's Coliseum 300 head. Both have reverb and EQ. The combo has an EVM-12L speaker and the head would be paired up with my 80's 2x12 vertical half-back cab with a Celestion 90 in the open top and an EVM-12L in the ported bottom.

 

I'm trying to decide which one to buy. Do you have any experience with these? Any insights? I'm inclined to go with the smaller amp for the sake of size, but willing to consider the more powerful head if there's a compelling sonic difference. (BTW, I can't audition the Coliseum - I'd be having it shipped to me.)

TieDyedDevil ..........

 

This is a hard call, as these are two very different amps. The MK III would be easier to move around by a long shot.

 

These amps sound very different, and feel very different. The bottom line is probably, for you to try to play examples of each at some store that may have some used ones.

 

Sorry I could not help more.

[jeangeniemusic]

hello Myles:

. You have basically made my guitar education with your posts on The EQ guitar forum. Many thanks for that.

I am in the process of buying a studio amp that will be used for recording only. I was set on a Vox ac30 until i read your posts about the THD univalve and Bivalve.

I tried the univalve and was really impressed by its tone and versatility. I have difficulty locating a bivalve to compare. Which one would you suggest I should get as a versatile recording tool : UV or BV? I am looking for an amp that can achieve good tone at low level and simple enough to allow me to recall the settings that work quickly. Also could you please recommand a specific cabinet to record with this amp? I know from various posts that you advocate 1X12 cabinets for recording could you suggest one? would the THD 2X12 cabinet work for that purpose?. I value your opinion and thank you for being so generous with your time and knowledge.

Jeangeniemusic

[myles_rose]

Originally posted by jeangeniemusic:

hello Myles:

. You have basically made my guitar education with your posts on The EQ guitar forum. Many thanks for that.

I am in the process of buying a studio amp that will be used for recording only. I was set on a Vox ac30 until i read your posts about the THD univalve and Bivalve.

I tried the univalve and was really impressed by its tone and versatility. I have difficulty locating a bivalve to compare. Which one would you suggest I should get as a versatile recording tool : UV or BV? I am looking for an amp that can achieve good tone at low level and simple enough to allow me to recall the settings that work quickly. Also could you please recommand a specific cabinet to record with this amp? I know from various posts that you advocate 1X12 cabinets for recording could you suggest one? would the THD 2X12 cabinet work for that purpose?. I value your opinion and thank you for being so generous with your time and knowledge.

Jeangeniemusic

jeangeniemusic..........

 

I see you are from Chicago from your profile. Great jazz and blues city, and just outside, is Victoria amp, perhaps my favorite amp builder!

 

First, thank you for the compliments.

 

The Vox AC-30 is a great amp, but not what I would call a studio amp. The weight alone is an issue, and it has one set of sounds.

 

The UV to me is a nicer studio and recording amp than the BV, from my personal point of view, as it is not as tight in a way, sort of has the sound and note swell in a nicer way to my ears.

 

Either amp has terrific tone controls that are very easy to use. The line outs on each of them is the same .... terrific ... transformer isolated.

 

On cabinets, this is again personal, but there is nothing like a single 12 and it's clarity. With two or more speakers, there are subtle differences in cone weights, etc., and there is minute phase cancellation. I prefer single 12's when recording, or playing blues, most forms of early rock and jazz live.

 

The THD 2x12 cabinet is one of those exceptions that proves the general rule. It is a grand cabinet, preferred by most folks over a lot of similar cabinets.

 

For a great inventory, use something like a Mesa 1x12 half back cab with the stock (Celestion) speaker, a nice 12" open back cab with something like a Jensen C12N or P-12R, and then have Mark Baier at Victoria, build you a light tweed cabinet for the Jensen mentioned above.

 

A 4x10 cab could be cool too.

 

The UV is a great amp.

[jeangeniemusic]

Myles:

Thank you for your answer. I am not sure if you thought that the THD cab would work for recording or just thought it is a great cab.

Again thank you for your time.

jeangeniemusic

[TieDyedDevil]

Originally posted by myles111:

Originally posted by TieDyedDevil:

Myles --

 

I have a line on two different Mesa/Boogie Mark IIIs - an early 90's simulclass combo and a late 80's Coliseum 300 head. Both have reverb and EQ. The combo has an EVM-12L speaker and the head would be paired up with my 80's 2x12 vertical half-back cab with a Celestion 90 in the open top and an EVM-12L in the ported bottom.

 

I'm trying to decide which one to buy. Do you have any experience with these? Any insights? I'm inclined to go with the smaller amp for the sake of size, but willing to consider the more powerful head if there's a compelling sonic difference. (BTW, I can't audition the Coliseum - I'd be having it shipped to me.)

TieDyedDevil ..........

 

This is a hard call, as these are two very different amps. The MK III would be easier to move around by a long shot.

 

These amps sound very different, and feel very different. The bottom line is probably, for you to try to play examples of each at some store that may have some used ones.

 

Sorry I could not help more.

Close enough, thanks. I've been able to find some anectdotes regarding the Mk3 Coliseum and the Mk3 combo that told me pretty much the same thing. I've got a pretty good idea what I can expect from the difference in output stages, but less of a clue about how they might be voiced differently (M/B apparently went through a number of revisions).

 

I guess I'll have to play 'em and listen.

[myles_rose]

Originally posted by jeangeniemusic:

Myles:

Thank you for your answer. I am not sure if you thought that the THD cab would work for recording or just thought it is a great cab.

Again thank you for your time.

jeangeniemusic

jeangeniemusic .........

 

I think the THD 2x12 cab is great for any application, live or recording.

[myles_rose]

Originally posted by TieDyedDevil:

Originally posted by myles111:

Originally posted by TieDyedDevil:

Myles --

 

I have a line on two different Mesa/Boogie Mark IIIs - an early 90's simulclass combo and a late 80's Coliseum 300 head. Both have reverb and EQ. The combo has an EVM-12L speaker and the head would be paired up with my 80's 2x12 vertical half-back cab with a Celestion 90 in the open top and an EVM-12L in the ported bottom.

 

I'm trying to decide which one to buy. Do you have any experience with these? Any insights? I'm inclined to go with the smaller amp for the sake of size, but willing to consider the more powerful head if there's a compelling sonic difference. (BTW, I can't audition the Coliseum - I'd be having it shipped to me.)

TieDyedDevil ..........

 

This is a hard call, as these are two very different amps. The MK III would be easier to move around by a long shot.

 

These amps sound very different, and feel very different. The bottom line is probably, for you to try to play examples of each at some store that may have some used ones.

 

Sorry I could not help more.

Close enough, thanks. I've been able to find some anectdotes regarding the Mk3 Coliseum and the Mk3 combo that told me pretty much the same thing. I've got a pretty good idea what I can expect from the difference in output stages, but less of a clue about how they might be voiced differently (M/B apparently went through a number of revisions).

 

I guess I'll have to play 'em and listen.

That's the best deal, play and try them each if you can.

[sgguitarzz]

Myles -

 

I received the Ampeg Reverberocket R212 I told you about and ordered all of the tubes you recommended (except the RCA 12AX7 NOS for V1- KCA had the same tube in a ANOS for a lot less so I took a shot). I have received some of the tubes so far and want to put them in. I just want to check with you about the tubes slots. Is V1 on this amp, looking from the back, the slot furthest to the right and V3 the tube closest to the power tubes? The amp came with all Sovteks which I assume were the original tubes. Doesn't sound too bad and I hope the new tubes will be even better. My KCA order arrived but I am waiting on my GT order (I ordered them both at the same time - tell your guys to get with it :-) ). Thanks.

[myles_rose]

Originally posted by sgguitarzz:

Myles -

 

I received the Ampeg Reverberocket R212 I told you about and ordered all of the tubes you recommended (except the RCA 12AX7 NOS for V1- KCA had the same tube in a ANOS for a lot less so I took a shot). I have received some of the tubes so far and want to put them in. I just want to check with you about the tubes slots. Is V1 on this amp, looking from the back, the slot furthest to the right and V3 the tube closest to the power tubes? The amp came with all Sovteks which I assume were the original tubes. Doesn't sound too bad and I hope the new tubes will be even better. My KCA order arrived but I am waiting on my GT order (I ordered them both at the same time - tell your guys to get with it :-) ). Thanks.

sgguitarzz .........

 

The ANOS will be fine.

 

V1 is closest to the input jack.

 

On your GT order, was this off the website, or a call in order or ???? If this is a website order, what is your order number? Email me at GT at techsupport@groovetubes.com and I can check on that for you.

 

Myles

[Gabriel E.]

Ok. Here's another question:

 

When played clean, my Sovtek Mig-50 has a much faster response than my Fender 5F4.

 

I'm assuming this is because of the sag from the 5V4 rectifier in the Fender. Is this the case? If so, what tube(s) would you recommend to speed up the attack? The tube chart specifies a 5U4G but that won't fit since a former owner cut the amp into a head.

 

Thanks

[myles_rose]

Originally posted by Gabriel E.:

Ok. Here's another question:

 

When played clean, my Sovtek Mig-50 has a much faster response than my Fender 5F4.

 

I'm assuming this is because of the sag from the 5V4 rectifier in the Fender. Is this the case? If so, what tube(s) would you recommend to speed up the attack? The tube chart specifies a 5U4G but that won't fit since a former owner cut the amp into a head.

 

Gabriel ..........

 

Very different amps for a start. If you look on my website in the rectifier info stuff, you will see the rise times also, of the different rectifiers. If your 5F4 super has a good power supply and good PS caps, you can try a solid state rectifier plug in, or a GZ34 / 5AR4, but be sure to check the bias, or go with a 6L6 tube set with lower numbers to keep the idle current within spec.

 

We can also try to go with a V1 5751 rather than the 12AY7 that was stock.

 

Thanks

[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