Feel free to ask Myles

[myles_rose]

Originally posted by Steevo:

Thanks for the info and the generous offer ... however, I'm in KY. I could probably measure those voltages myself. I've got 'The Tube Amp Book' by Aspen Pittman and its got all the schematics in there. S.

Feel free to give me a call, email, or write back here.

[myles_rose]

Originally posted by Mike1959:

Hi Myles,

 

I thought Id give you an update on the ailing Nomad. Spoke with the Mesa tech today. He hasn't finished his inspection yet but he was able to tell me what he had found so far -

 

The opto-circuits are blown. He said these components should last forever; they don't generally go unless, as he put it, 'the amp has had a hi-voltage up it's backside'.

 

As a result of the problems with the opto-circuits, channels 2 and 3 have channel 1 superimposed over them (I think that's the word he used).

 

There is a 100Hz ripple that's very prominent in channel 2 - that's the low level modulation that I was complaining about.

 

He also said that someone had botched a replacement electrolytic replacment. That is most likely the previous tech's handy work. Whilst I don't think he caused the problem, he assured me he had worked on Nomads before. He said he had repaired another clients amp, and he was very impressed with his work. I am very unhappy that he claimed to be able to service Mesa amps, but clearly didnt know how to either analyse the circuit and determine the problem, or replace components correctly.

 

There is a possible short in the circuit somewhere. He is now awaiting some photos of the circuit boards from Mesa USA for comparison. He said sometimes you can zap the bridge with high voltage.

 

AND THAT'S THE GOOD NEWS. If the PCBs are beyond repair, replacements are not available and the cost of repairing would be prohibitive, as in 'build an amp from scratch'.

 

Once he has finished the inspection, he will supply me with a report and photographic evidence. If the amp cannot be repaired within reasonable cost, I will contact either the seller or the other technician, or both, depending on his findings. As it stands now it is not good. Ive spent £700 on the amp, and a further £200 for the service.

 

Excuse me while I go and drown my sorrows

 

Mike

Mike

 

It sounds like you have a real mess on your hands.

 

Mesa has a really funny sort of warranty policy if the amp is stock.... at least if the amp is taken to the Mesa store in Hollywood and maybe everywhere .... If something breaks that should have lasted for a decade they generally fix the problem under warranty ... even when the amp is no longer under warranty.

 

Mesa is sort of a strange company when it comes to service and support. They are one of the big four .... Fender, Marshall, Vox, and Mesa ... and maybe even sell more these days than Vox (I don't know personally).

 

In any case, they are a very large company and sell a LOT of amps yet their customer service and support is top notch. They fix things that should not even be warranty issues a lot of the time .... actually I'd venture to say most of the time.

 

To find the level of service and support in such a large company is very unusual these days.

 

In the future, if you have a Mesa product that has any sort of issue I would take it to a Mesa dealer, not somebody who says they have worked on Mesa amps at some point in time. Mesa is pretty picky about their parts selection and a non Mesa dealer may throw in just about anything if they do not have Mesa parts. Even if the amp is NOT under any warranty, the real Mesa tech will be much faster as he is used to the amps and the fastest way to get to the problem physically. Real Mesa parts are also pretty inexpensive. They buy in huge quantities so their prices are low and they pass the good pricing to the folks that buy from them. Look at their tubes as an example .... really darn cheap for output sets and they are really nicely matched for proper use in a fixed bias Mesa amp. They also have a great warranty period on tubes to boot.

 

The killer for decades was a great sturdy A/B switch. It was really well constructed and sold for 1/2 of what anything else out there sold for at about $24.95 or $29.95. Now they went to $49.95 I think (I may be wrong) but even at that price they are one of the best values on the market.

[Mike1959]

Myles,

 

I wish i'd known about that. It wasn't a deliberate attempt to not see an authorised Mesa tech. I saw an ad in the Guitarist magazine and gave them a call.

 

Assuming the worse, PCB board is FCUK'd and the responsible party (previous owner or tech) don't want to know, and knowing that Mesa don't have any replacement boards, would you know if there is any chance of sourcing a replacement? I'm making a further assumption that even if I could obtain a replacment, it could be fitted? To think I could have bought three used 50 watt Marshall amps for the same initial outlay.

 

I have invested so much money, time and effort, I want to exhaust all reasonable possibilities before I take the 'sell for parts' route.

 

Once again, thank you for your trouble Myles.

 

Mike

[myles_rose]

Originally posted by Mike1959:

Myles,

 

I wish i'd known about that. It wasn't a deliberate attempt to not see an authorised Mesa tech. I saw an ad in the Guitarist magazine and gave them a call.

 

Assuming the worse, PCB board is FCUK'd and the responsible party (previous owner or tech) don't want to know, and knowing that Mesa don't have any replacement boards, would you know if there is any chance of sourcing a replacement? I'm making a further assumption that even if I could obtain a replacment, it could be fitted? To think I could have bought three used 50 watt Marshall amps for the same initial outlay.

 

I have invested so much money, time and effort, I want to exhaust all reasonable possibilities before I take the 'sell for parts' route.

 

Once again, thank you for your trouble Myles.

 

Mike

Mike,

 

I would contact Mesa in the USA .... they always have had every single part of any amp they ever made or a source.

[Mike1959]

Myles,

 

The tech told me that replacing the board is not an option. He wasn't specific when he spoke but I took it to mean that replacments are not available, as this model is discontinued. From what you say, I am now thinking he meant refitting them as an after service is not possible - something to do with the way they are fitted into the chasis.

 

I will ask him to confirm. Thanks.

 

Mike

[myles_rose]

Originally posted by Mike1959:

Myles,

 

The tech told me that replacing the board is not an option. He wasn't specific when he spoke but I took it to mean that replacments are not available, as this model is discontinued. From what you say, I am now thinking he meant refitting them as an after service is not possible - something to do with the way they are fitted into the chasis.

 

I will ask him to confirm. Thanks.

 

Mike

Contact Mesa directly.

[Bluesape]

Hey Myles,

 

Do you anything about Gibson Mercury amps? There's one locally - a 1965 30 watt stack with 2x12 cab. It's huge, enormous - easily the size of a modern 100 watt Marshall. Any info is appreciated.

 

thanks

 

Reif

[Dr. Ellwood]

Hi Myles, well the 1962 Fender Pro Amp is now completed and sounds great thanks in part to those great Groove Tube power tubes. Caevan gave me some additional ideas for expanding the capabilities and variety of tones available with the Pro. He said that I could use a A/B switching device to choose my normal and vibrato channel (with the presence control) to get very different and interesting combinations of tone. He said that the preamp tubes that control these independent channels could be tailored to accomplish this. What would be a good set of preamp tubes to start with to do the experimentation? I want to keep the final power tubes the same though. I put up some sound samples of the Brown Pro on SoundClick http://www.soundclick.com/bands/1/theroadhogband_music.htm

to show how the amp sounds now, what you would hear is the Pro Amp on the tremelo channel. Got any ideas for me to try Myles, thanks Lee

[myles_rose]

Originally posted by Bluesape:

Hey Myles,

 

Do you anything about Gibson Mercury amps? There's one locally - a 1965 30 watt stack with 2x12 cab. It's huge, enormous - easily the size of a modern 100 watt Marshall. Any info is appreciated.

 

thanks

 

Reif

Reif,

 

All the Gibson amps of this period had some pretty cool aspects. Play one if you have the chance. It may be something you like or not... user preference.

 

They were pretty nicely done and are fun amps.

[myles_rose]

Originally posted by ellwood:

Hi Myles, well the 1962 Fender Pro Amp is now completed and sounds great thanks in part to those great Groove Tube power tubes. Caevan gave me some additional ideas for expanding the capabilities and variety of tones available with the Pro. He said that I could use a A/B switching device to choose my normal and vibrato channel (with the presence control) to get very different and interesting combinations of tone. He said that the preamp tubes that control these independent channels could be tailored to accomplish this. What would be a good set of preamp tubes to start with to do the experimentation? I want to keep the final power tubes the same though. I put up some sound samples of the Brown Pro on SoundClick http://www.soundclick.com/bands/1/theroadhogband_music.htm

to show how the amp sounds now, what you would hear is the Pro Amp on the tremelo channel. Got any ideas for me to try Myles, thanks Lee

Lee,

 

A lot of folks love the GT TT kit as it gives you three very different tubes to get three different tones and results.

 

http://www.groovetubes.com/product.cfm?Product_ID=1768

[Dr. Ellwood]

Great! thanks I will order them tomorrow and give em a try!

[muzakal]

hi myles,

 

i bought an amp on e-bay and wanted to know if you can recommend anyone in the n.y.c. area for a routine amp checkup.

thanks

[myles_rose]

Look in my Techs area on my website.

[muzakal]

thanks

[GTIDSLF12X]

Hello Myles,

What is your take on the Soul o-50 head/combo? Nobody seems to be using these amps and I can't find any solid information on the web about them. Seems like the Soul o-45 did much better than the 50's. Enlighten me please.

[myles_rose]

Originally posted by GTIDSLF12X:

Hello Myles,

What is your take on the Soul o-50 head/combo? Nobody seems to be using these amps and I can't find any solid information on the web about them. Seems like the Soul o-45 did much better than the 50's. Enlighten me please.

The S-50 is a much newer amp and has three selectable gain stages in the front end. It is a very different amp than the S-45.

 

The owner's manual is here:

 

http://www.groovetubes.com/assets/2047_S50%20Manual%20.pdf

[GTIDSLF12X]

Hello Myles,

What is your take on the Soul o-50 head/combo? Nobody seems to be using these amps and I can't find any solid information on the web about them. Seems like the Soul o-45 did much better than the 50's. Enlighten me please.

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

 

The S-50 is a much newer amp and has three selectable gain stages in the front end. It is a very different amp than the S-45.

 

The owner's manual is here:

 

http://www.groovetubes.com/assets/2047_S50%20Manual%20.pdf

 

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

Myles S. Rose

 

Hello Myles,

Thanks for the reply - I have read the manual and the release sheet prior to posting. Have you used this amp? If so - does it take pedals well? does it need pedals? are there seperate adjustments for each output tube? Is the "3 stage bias adjustment" front end the same as having a high and low imput? (except adding a third one could call medium)"it's avery different amp than the S45" In what way would you say they are different? Thanks for your time - I am just trying learn as much as possible about this amp.

[myles_rose]

Originally posted by GTIDSLF12X:

Hello Myles,

What is your take on the Soul o-50 head/combo? Nobody seems to be using these amps and I can't find any solid information on the web about them. Seems like the Soul o-45 did much better than the 50's. Enlighten me please.

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

 

The S-50 is a much newer amp and has three selectable gain stages in the front end. It is a very different amp than the S-45.

 

The owner's manual is here:

 

http://www.groovetubes.com/assets/2047_S50%20Manual%20.pdf

 

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

Myles S. Rose

 

Hello Myles,

Thanks for the reply - I have read the manual and the release sheet prior to posting. Have you used this amp? If so - does it take pedals well? does it need pedals? are there seperate adjustments for each output tube? Is the "3 stage bias adjustment" front end the same as having a high and low imput? (except adding a third one could call medium)"it's avery different amp than the S45" In what way would you say they are different? Thanks for your time - I am just trying learn as much as possible about this amp.

I will try to answer all your questions ....

 

I have not only used this amp but I am pretty close friends with the designer Jimmy Wigle. I play these amps a few times a week as we use them for tube testing because the special design output transformer in the S-50 can handle the EL34, 6L6, 6550, and KT88.

 

It takes pedals very well. Does it need pedals? Does a Fender or Marshall "need" pedals? That is really user preference.

 

There is a single bias supply for the duet, just as in most amps. The reason that a few amps today have seperate bias pots for each half of the output circuit is to supposedly negate the need for matched tubes. This really does not work as this only would apply to the tubes at idle and not through the tube's complete operating range. With dynamically matched output tubes a single bias adjustment is what is wanted.

 

On the high and low input thought ... nope, not the same. Generally amps that have high and low inputs have a 3dB or 6dB difference between the two. The S-50 and S-30 have completely different gain structures. The low level is sort of Fender blackface, the mid is sort of Marshall Plexi era (and the amp does have a cathode follower tone stack as did the plexis and the tweed bassman), and the high level is sort of JCM 900+. There is also a pull boost function on the volume (foot switchable by the way) that gives each of these three settings another level (so six settings in all). In the high position with the switch pulled the amp is VERY gainy and very agressive.

 

The amp is different from the S-45 in the same way a BMW 535 is different from a Toyota Avalon. Totally different amps. The S-45's front end has a design that keeps the front end from getting overloaded from hot output pedals. There are many other differences too. The only thing alike in the amps is the GT badge. The chassis are even different to the point of not even being the same width or size.

[Steevo]

QUOTE]Steevo ....

 

I would first pop in a new 6V6 and 12AX7.

 

If this does not make it all better then the speaker needs to be checked. I would also check the voltages on the plates of the preamp tube and the output tube or have a tech do this. It is fast and easy for a tech. If you are near Los Angeles I would be happy to do this for you for nothing.

 

They are pretty darn cool amps. [/QB]

 

Hey Myles, I got my Groove Tubes today and swapped them into the '65 Champ. BIG difference already. However, there is a buzz that sound physical/mechanical ... the speaker may be in trouble. The speaker does not have the blue jensen sticker on it so I don't know what kind it is. If I need to replace it, where should I start?

 

Oh, by the way, I opened up my UPS package and found a matched set of 6V6's instead of just one! Wow! Either that was a very nice gesture or I just got someone in shipping in trouble. Let me know if I need to return the extra. Many thanks. S.

[myles_rose]

Originally posted by Steevo:

QUOTE]Steevo ....

 

I would first pop in a new 6V6 and 12AX7.

 

If this does not make it all better then the speaker needs to be checked. I would also check the voltages on the plates of the preamp tube and the output tube or have a tech do this. It is fast and easy for a tech. If you are near Los Angeles I would be happy to do this for you for nothing.

 

They are pretty darn cool amps.

Hey Myles, I got my Groove Tubes today and swapped them into the '65 Champ. BIG difference already. However, there is a buzz that sound physical/mechanical ... the speaker may be in trouble. The speaker does not have the blue jensen sticker on it so I don't know what kind it is. If I need to replace it, where should I start?

 

Oh, by the way, I opened up my UPS package and found a matched set of 6V6's instead of just one! Wow! Either that was a very nice gesture or I just got someone in shipping in trouble. Let me know if I need to return the extra. Many thanks. S. [/QB]

 

On the speaker ... you can have it reconed by there are a lot of great ones on the market that are not pricy. If you find a tear in yours (hold it up to the light), a little trick .... clear nail polish for the small cracks .... and if it's a big tear, a single sheet of toilet paper with clear nail polish works wonders.

 

On the duet of matched tubes .... what duet? No, it is really a single tube you must have.... or perhaps it had a clone on the way to you so you would now have an exact match as a spare? Hummmm .... it is a mystery I would guess. I'd look closer .... it may be smoke ... and MIRRORS and there is just a "reflection" of one tube in a nearby mirror perhaps. I cannot explain it!

[GTIDSLF12X]

Hello Myles,

Thanks for the reply - I have read the manual and the release sheet prior to posting. Have you used this amp? If so - does it take pedals well? does it need pedals? are there seperate adjustments for each output tube? Is the "3 stage bias adjustment" front end the same as having a high and low imput? (except adding a third one could call medium)"it's avery different amp than the S45" In what way would you say they are different? Thanks for your time - I am just trying learn as much as possible about this amp.

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

 

I will try to answer all your questions ....

 

I have not only used this amp but I am pretty close friends with the designer Jimmy Wigle. I play these amps a few times a week as we use them for tube testing because the special design output transformer in the S-50 can handle the EL34, 6L6, 6550, and KT88.

 

It takes pedals very well. Does it need pedals? Does a Fender or Marshall "need" pedals? That is really user preference.

 

There is a single bias supply for the duet, just as in most amps. The reason that a few amps today have seperate bias pots for each half of the output circuit is to supposedly negate the need for matched tubes. This really does not work as this only would apply to the tubes at idle and not through the tube's complete operating range. With dynamically matched output tubes a single bias adjustment is what is wanted.

 

On the high and low input thought ... nope, not the same. Generally amps that have high and low inputs have a 3dB or 6dB difference between the two. The S-50 and S-30 have completely different gain structures. The low level is sort of Fender blackface, the mid is sort of Marshall Plexi era (and the amp does have a cathode follower tone stack as did the plexis and the tweed bassman), and the high level is sort of JCM 900+. There is also a pull boost function on the volume (foot switchable by the way) that gives each of these three settings another level (so six settings in all). In the high position with the switch pulled the amp is VERY gainy and very agressive.

 

The amp is different from the S-45 in the same way a BMW 535 is different from a Toyota Avalon. Totally different amps. The S-45's front end has a design that keeps the front end from getting overloaded from hot output pedals. There are many other differences too. The only thing alike in the amps is the GT badge. The chassis are even different to the point of not even being the same width or size.

 

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

Myles S. Rose

 

www.groovetubes.com

 

www.guitaramplifierblueprinting.com

 

Models for your CD cover artwork, live performance work or video work can be found at:

 

www.saunders-stewart-models.com

 

 

Hello Myles,

Thanks for the detailed answers.

[myles_rose]

You are quite welcome

[J J]

Myles,

 

I was thinking on buying an attenuator for my Fender Deville. Now i was thinking on buying one of these from the Weber site . The deville is 8 ohm and 60 watts. Would it be possible to run the amp through a 50 watt attenuator and be ok, or do I need to get like a 100 watt one?

 

I'd like to get the hotplate, but im kinda strapped. Do these attenuators look alright?

 

thanks

[Steevo]

.... Hummmm .... it is a mystery I would guess. I'd look closer .... it may be smoke ... and MIRRORS and there is just a "reflection" of one tube in a nearby mirror perhaps. I cannot explain it!

I think you just did.

 

Can I borrow your ears? I believe the speaker is fine. I removed it and there is no visible damage. The voice coil moves freely (although it seems to bottom out quickly while going back). There is a buzz on the low E string that is not supposed to be there I'm sure. I recorded a short sound clip for you to hear it. What do you think this is? 1965 BF Champ - Sound Clip

 

Thanks in advance. S.

 

FWIW, here's a picture for how I recorded it:

 

http://www.shrewsberry.net/champ/champ2.jpg

[myles_rose]

Originally posted by J J:

Myles,

 

I was thinking on buying an attenuator for my Fender Deville. Now i was thinking on buying one of these from the Weber site . The deville is 8 ohm and 60 watts. Would it be possible to run the amp through a 50 watt attenuator and be ok, or do I need to get like a 100 watt one?

 

 

I'd like to get the hotplate, but im kinda strapped. Do these attenuators look alright?

 

thanks

For the Loggins & Messina Tour we used Dr. Z Airbrakes in each of Kenny's amps. They need no power, are very transparent, simple and reliable, designed by Ken Fisher (Trainwreck) and there is only one model for all impedances. The device will easily handle over 100 watts also. Many other units were considered.

 

http://www.drzamps.com/airbrake.html

[myles_rose]

Originally posted by Steevo:

.... Hummmm .... it is a mystery I would guess. I'd look closer .... it may be smoke ... and MIRRORS and there is just a "reflection" of one tube in a nearby mirror perhaps. I cannot explain it!

I think you just did.

 

Can I borrow your ears? I believe the speaker is fine. I removed it and there is no visible damage. The voice coil moves freely (although it seems to bottom out quickly while going back). There is a buzz on the low E string that is not supposed to be there I'm sure. I recorded a short sound clip for you to hear it. What do you think this is? 1965 BF Champ - Sound Clip

 

Thanks in advance. S.

 

FWIW, here's a picture for how I recorded it:

 

http://www.shrewsberry.net/champ/champ2.jpg

It is hard to tell from a clip but it sounds to me as if something is vibrating in the amp itself.

[Steevo]

It is hard to tell from a clip but it sounds to me as if something is vibrating in the amp itself.

I'm pretty sure this is electronic. At the beginning of the clip, I play a A string open, and then an E string open and let it ring out. At the end of that long E string you'll hear the buzz/distortion kind of fizzle out ... in an electronic kind of way. At first, I thought it was mechanical/physical but now I don't think so ... everything seems tight. Maybe I'll try an external speaker to take that all out of the equation. Thanks for listening!

 

S

[myles_rose]

Try that external speaker idea.

[BillWelcome Home Studios]

Miles,

 

Looking for someone to repair a Vox Bulldog speaker. Is there a reconing company that you are aware of?

 

Bill

[myles_rose]

Originally posted by bpark@prorec.com:

Miles,

 

Looking for someone to repair a Vox Bulldog speaker. Is there a reconing company that you are aware of?

 

Bill

Bill ....

 

Orange County Speaker Repair is one of the best in the business.