Feel free to ask Myles

[DavidMPires]

Hi Myles

 

I lurk around on the Lowdown alot but not so much here, I have a friend who ows a Mesa Boogie Stilleto Combo and plays a telecaster he wants to change pick ups for ones with more lows as he finds the stock ones too trebly.

 

Thanks for your help.

 

david

[myles_rose]

Hi Myles

 

I lurk around on the Lowdown alot but not so much here, I have a friend who ows a Mesa Boogie Stilleto Combo and plays a telecaster he wants to change pick ups for ones with more lows as he finds the stock ones too trebly.

 

Thanks for your help.

 

david

 

David,

 

Pickup selection is an ultra personal issue and there are so many variables.

 

 

[mdrs]

Hi Myles

 

I lurk around on the Lowdown alot but not so much here, I have a friend who ows a Mesa Boogie Stilleto Combo and plays a telecaster he wants to change pick ups for ones with more lows as he finds the stock ones too trebly.

 

Thanks for your help.

 

david

 

David,

 

Contact Lindy Fralin or Seymour Duncan directly. They'll have suggestions for your friend.

 

http://www.fralinpickups.com/

 

http://www.seymourduncan.com/index.php

 

[paully]

Hi Myles. I'm brain-picking again. I've seen feedback circuits in a lot of amp schemos but this one, for an Ampeg V4, adds a .001 cap in parallel with the traditional limiting resistor. This is the only amp I've seen it on, and am wondering why Ampeg might have included it. Speculations appreciated. Thanks.

 

http://i125.photobucket.com/albums/p71/goosefat/V4.jpg

 

Best, Paul

 

[myles_rose]

Hi Myles. I'm brain-picking again. I've seen feedback circuits in a lot of amp schemos but this one, for an Ampeg V4, adds a .001 cap in parallel with the traditional limiting resistor. This is the only amp I've seen it on, and am wondering why Ampeg might have included it. Speculations appreciated. Thanks.

 

http://i125.photobucket.com/albums/p71/goosefat/V4.jpg

 

Best, Paul

 

Probably there to tame down possible ocillations.

 

 

[paully]

>>>>>>>>>>>>>>

Thanks Myles. That's the general concensus(a lo-pass filter).

 

Best, Paul

[Junior 1]

Hi Myles,

I bought a Gibson GA-5, Les Paul Junior amp on closeout at MF. I love the way it sounds, but has a low level hum that is always present, but does not get louder with volume. Have you had any expierience with these guys? I've been a Valve Junior guy for a while and the head version is silent. The Gibson is not dark like the VJ and I really like the sound. Just wondering about that hum.

Thanks

Anthony

[myles_rose]

Hi Myles,

I bought a Gibson GA-5, Les Paul Junior amp on closeout at MF. I love the way it sounds, but has a low level hum that is always present, but does not get louder with volume. Have you had any expierience with these guys? I've been a Valve Junior guy for a while and the head version is silent. The Gibson is not dark like the VJ and I really like the sound. Just wondering about that hum.

Thanks

Anthony

 

You may have a bad preamp tube, a bad cap in the power supply or a bad ground in the amp.

 

 

[Junior 1]

Thanks Myles, I'll start with the tube.

Anthony

[myles_rose]

Thanks Myles, I'll start with the tube.

Anthony

 

Try that first and let me know what happened.

[Trucks]

Hi Myles,

 

I am looking into getting a little Fender Champ, If I wanted to run a US valve amp set for 110v in the UK at 240v, what would be the best thing to do? An external transformer or mod it, etc? Do you know if this changes the tone of the amp?

 

Thanks

 

Lee

[myles_rose]

Hi Myles,

 

I am looking into getting a little Fender Champ, If I wanted to run a US valve amp set for 110v in the UK at 240v, what would be the best thing to do? An external transformer or mod it, etc? Do you know if this changes the tone of the amp?

 

Thanks

 

Lee

 

Lee,

 

If you are talking about a vintage amp then leave it stock and use a step down transformer in the UK. These are reliable and inexpensive and work fine. You can find them at many electronics stores and suppliers. Do not change anything on a vintage amp as it will lower the value.

 

If you are looking at a new reproduction then have them wire it form UK voltage. Some of the best Champs on the globe come Victoria Amp ( www.victoriaamp.com ) and Pierson Amps ( www.pierson-amps.com ). Both these folks amps will increase in value over time as they are very well made and have a strong reputation.

 

 

[Trucks]

Thanks for the info, Myles. I will look into the new reproductions, I had intially been looking for an old blackface champ, but they are hard to come by!

[myles_rose]

Thanks for the info, Myles. I will look into the new reproductions, I had intially been looking for an old blackface champ, but they are hard to come by!

 

Got it. The reproductions I mentioned were tweed era. For blackface look on ebay.

 

 

[steve f]

Myles, I had questions about Shuguang 12AX7 tubes in amps with DC heaters.

 

1) Do you know if there are any problems using the 8th & 9th Gen Shuguang 12ax7s in these type amps?

 

2) Do you know the current draw of the Shuguang 12ax7s (is it in the normal range for 12ax7s?).

[myles_rose]

Myles, I had questions about Shuguang 12AX7 tubes in amps with DC heaters.

 

1) Do you know if there are any problems using the 8th & 9th Gen Shuguang 12ax7s in these type amps?

 

2) Do you know the current draw of the Shuguang 12ax7s (is it in the normal range for 12ax7s?).

 

 

No problems at all and they fall right in spec heater wise with all other 12AX7s.

 

 

[Junior 1]

Hi Myles,

I solved my GA-5 hum problem. I use a different outlet! Now it is almost dead silent. I'm going to connect an 8 ohm 12 inch cab to the little monster and was wondering what I will lose in sound quality going from the 4 ohm output to an 8 ohm cab. There is an 8 ohm wire coming from the transformer, but I'd rather not install an additional jack right now.

Thank You

Anthony

[myles_rose]

Hi Myles,

I solved my GA-5 hum problem. I use a different outlet! Now it is almost dead silent. I'm going to connect an 8 ohm 12 inch cab to the little monster and was wondering what I will lose in sound quality going from the 4 ohm output to an 8 ohm cab. There is an 8 ohm wire coming from the transformer, but I'd rather not install an additional jack right now.

Thank You

Anthony

 

Very typical .... grounding issues in homes.

 

Happy playing.

 

[Junior 1]

Thanks Myles. How about that 4 ohm output to the 8 ohm cab?

Thanks

Anthony

[myles_rose]

Thanks Myles. How about that 4 ohm output to the 8 ohm cab?

Thanks

Anthony

 

 

Anthony,

 

No problem with a higher impedance speaker to a low ohm tap, you may loose a bit of power but it is safe.

 

BUT ... never go the OTHER way .... a 4 ohm speaker into an 8 or 16 ohm jack.

 

 

[Junior 1]

Thanks Myles.

[myles_rose]

Thanks Myles.

 

You are quite welcome

 

 

[Salad Days]

Hi Myles,

Hoping you can help me.

 

I have a 1993 Marshall 1987x reissue that originally came with 5881 valves.

I'v been using a set of JJ e34L's for around a year now at the reccomendation of bob@eurotubes and its been great until recently when my amp went down while playing it cranked.

 

So I took it to a tech who says I shouldn't be using el34 types in my amp as it has different value screen resistors (among other things) to accomodate the 5881's and i was lucky my amp wasnt fried.

 

I emailed the Bob@eurotubes again who reassured me It should be fine with the e34l's. I trust bob's judgement generally but that sound control tech has me paranoid so I wanted to gather a third opinion.

 

Cheers,

Rich

 

[myles_rose]

Hi Myles,

Hoping you can help me.

 

I have a 1993 Marshall 1987x reissue that originally came with 5881 valves.

I'v been using a set of JJ e34L's for around a year now at the reccomendation of bob@eurotubes and its been great until recently when my amp went down while playing it cranked.

 

So I took it to a tech who says I shouldn't be using el34 types in my amp as it has different value screen resistors (among other things) to accomodate the 5881's and i was lucky my amp wasnt fried.

 

I emailed the Bob@eurotubes again who reassured me It should be fine with the e34l's. I trust bob's judgement generally but that sound control tech has me paranoid so I wanted to gather a third opinion.

 

Cheers,

Rich

 

Rich,

 

On this one your tech is right and Bob is wrong which surprises me.

 

The Marshall amps that were factory delivered with 5881/6L6s generally have 470 ohm 2-3 watt screen resistors and these are not right at all for an EL34 amp that has 1k ohm 5 watters.

 

A typical 6L6 tosses off about 3 watts off the screen at full bore in your amp vs 8 watts per tube with an EL34.

 

I am surprised at your luck in not having bigger problems much faster.

 

I am more surprised that Marshall would deliver a 1987x reissue with 6L6/5881 tubes as that amp NEVER used that tube and ALWAYS used the EL34.

 

Maybe have your tech check the screen resistors. If the are 1k / 5 watters (that is what a 1987x should have) then an EL34 is fine, and preferred. Bias to 36-38mA with EL34's if you have the proper screen resistors.

 

I would look at the part number on the output transformer and verify whether it is a 6L6 or EL34 output transformer. This should also be for EL34's if the amp was a proper reissue. If the output transformer is for 6L6's (your tech can measure this fast and easy) then this is one more thing that is not right with the amp and then stick to 6L6 types.

 

So ... at this point, once again ....

 

Your tech is on the money.

 

Bob is mistaken unless he knows for a fact that your amp has the proper parts to run EL34s. Bob may have assumed that Marshall stuck to the original output configuration. It was even a surprise to me to hear that Marshall would do something so yucky as to use a 6L6 tube type in a 50 watt plexi reissue! Then again ... was the amp delivered this way new from Marshall or did you get it second hand?

 

 

[Salad Days]

Yeah the tech told me it had the marshall mods to run 5881's and that the e34l's i was using were going to be problematic.

 

I probably didnt give bob enough information when i discussed it with him. But I didnt want to harass the guy with emails about specifics i'd perhaps neglected. He's always been on the ball previously.

 

Can you reccomend me a set of valves to use in my situation?

[myles_rose]

Yeah the tech told me it had the marshall mods to run 5881's and that the e34l's i was using were going to be problematic.

 

I probably didnt give bob enough information when i discussed it with him. But I didnt want to harass the guy with emails about specifics i'd perhaps neglected. He's always been on the ball previously.

 

Can you reccomend me a set of valves to use in my situation?

 

If we are talking 5881's then I personally would go with the 6L6CHP in a #7 rating biased at 32mA which are smoother to my ears than the 6L6S or the 5881WXT by Sovtek.

 

 

[Paul K]

Howdy Myles

 

This might already have been dealt with in this thread, but at 140-some-odd pages I'm going to take the lazy man's way out.

 

Over at the bass player side of this forum we're wrestling with the safety issues involved with low level amp repair, tube replacement, and the like. Some say that it's a job best left to The Tech's (more of these folks live across the pond in 240 volt land), others (like me) are DIY'ers to the bone. Can you refer us to a web page of safety tips that can remove some of the electrical Voo-Doo from the equation? Most of these issues appear to be involving electrical charges that is still stored in capacitors after the unit has been powered down.

 

Thanks!

Paul K

[myles_rose]

Howdy Myles

 

This might already have been dealt with in this thread, but at 140-some-odd pages I'm going to take the lazy man's way out.

 

Over at the bass player side of this forum we're wrestling with the safety issues involved with low level amp repair, tube replacement, and the like. Some say that it's a job best left to The Tech's (more of these folks live across the pond in 240 volt land), others (like me) are DIY'ers to the bone. Can you refer us to a web page of safety tips that can remove some of the electrical Voo-Doo from the equation? Most of these issues appear to be involving electrical charges that is still stored in capacitors after the unit has been powered down.

 

Thanks!

Paul K

 

 

Go hit my GAB website ... on the first page are about a dozen of the coolest things on the planet in the music bizz. Look for Dave Hunter's book. Buy it.

 

 

[Salad Days]

Thanks myles!

Sorry to keep bugging you but do you think i'd be able to use kt88's?

[myles_rose]

Thanks myles!

Sorry to keep bugging you but do you think i'd be able to use kt88's?

 

No problem-o about 'bugging me'

 

On the KT88s .... big problem if you do not have 1K ohm 5 watt screen resistors. Big time smoke very fast.