Feel free to ask Myles

[not coaster MODERATOR]

Myles

 

I have a friend with a nylon acoustic. He's an average player and it's an average guitar. What will it take to put a pickup in that thing?

[myles_rose]

Originally posted by Cereal:

Myles

 

I have a friend with a nylon acoustic. He's an average player and it's an average guitar. What will it take to put a pickup in that thing?

Cereal,

 

There are pickups in all ranges. For a classical or nylon strung guitar, there are some nice contact pickups that work fairly well. Then you can go right on up the scale with a piezo bridge and buffered preamps etc.

 

The best fellow to talk to is either:

 

David Neely at 323-850-7043

 

or

 

"the amazing Nick" at 818-344-8300 who is the fellow that takes care of all the guitars over at Norman's Rare Guitars.

 

or

 

In Westwood, call Pat at Westwood Music at 310-378-4251. Pat was at Coruthers (I butchered the spelling there I'm sure) for about a decade before coming to westwood.

 

Those are my favorite guitar folks, but there are a lot of nice ones around, so somebody here may also have a suggestion.

 

Regards,

[not coaster MODERATOR]

Thanks Myles. I'll pass all 3 numbers along.

[MesaUser]

Myles, I have a 3 chan. Mesa Rectifier that I pull 2 tubes....which of course leaves me using 2. I have the Ohmage and everything matched. My question is...will this hurt my amp in anyway by runnin it like this for long periods of time. By the way...Im using Mesa labled Svet el34's. Thanks!

[myles_rose]

Originally posted by MesaUser:

Myles, I have a 3 chan. Mesa Rectifier that I pull 2 tubes....which of course leaves me using 2. I have the Ohmage and everything matched. My question is...will this hurt my amp in anyway by runnin it like this for long periods of time. By the way...Im using Mesa labled Svet el34's. Thanks!

MesaUser,

 

If you are using a 100 watt Mesa, which I think is what you are saying here, you can pull two of the tubes to make this into a 50 watt amp with no problems.

 

There are a few things to remember though ....

 

1. If you are using a 16 ohm cabinet, plug it into the 8 ohm speaker jack. If you are using an 8 ohm cabinet, plug it into the 4 ohm jack. Your output tubes have impedience too, and you need to keep this matched.

 

2. Swap the tubes you use with the ones you pulled every once in a while so they do not end up as one pair with a lot of wear, and the other unused pair stronger.

 

By doing this 50 watt setup, the heater current needs are dropped on your amp and your power transformer is under less strain too, as well as not having to drive the other pair of tubes, so it gives your amp a little rest in a manner of speaking. Keep in mind also, that you still have a beefy power supply that was designed for a 100 watt amp, so don't expect some of the sound associated with a 50 watt amp when its power supply is taxed. This is one of the reasons some folks like Jeff Beck prefer 50 watt amps rather than just pulling tubes out of 100 watters, but you will get your amp to get into that nice range of output distortion at more rational levels, and it will sound pretty nice.

 

Regards,

[OldManMetal]

Myles, I have a couple of questions I hope you can help me with. Both deal with tubes.

 

1. What tubes do you recommend for a Peavey Delta Blues 210 combo, used for everything from clean tones to rockin' blues tones?

 

2. What tubes do you recommend for a Mesa Boogie .50 Caliber + head used for mainly heavier tones?

 

Thanks for you help

[Cornforduser]

Myles,

How great to know about the new GE 6L6!!!!

BTW, What would you do in my amp ?

Mullard ECC83 + GE 5751 + Mullard ECC83 (driver)

Mullard ECC83 + Mullard ECC83 + GE 5751 (driver)

What would be the effect of each ???

[myles_rose]

Originally posted by jazzcaster:

A quick question for Myles! I have a new Fender Pro Reverb (Pro Tube Series). I love it. I want to experiment with some tube swaps. My question is....which tubes (ie. function, like tremolo, reverb etc.)correspond to which location on the chassis (ie. V1, V2, V3 etc.). I have the schematic that came with the amp, but I don't know how to read it....it's almost all Greek to me!).

 

Thanks Myles (or anyone else who can help).

jazzcaster,

 

Here is a later answer as I get deeper into these amps.

 

First off, you are going to have to follow the tube chart inside the amp, as these puppies are laid out a bit differently than most amps. The phase inverter is still the closest to the output tubes, but being that the output tubes are about in the center of the amp, it makes for some unique thinking.

 

In any case, here is sort of what happens in this amp:

 

The input jack feeds V1A. This also feeds the gain control on the gain channel. It also feeds the normal channels tone circuit, and the normal channels volume control, which feeds V1B, for the normal channel's next gain stage. This feeds V3B, and that feeds V8A (the effects send) and then comes back in with V8B, the effects return.

 

V5B is used to supply the preamp out jack on the back panel to send a signal to a board, another amp, or house system. Reverb is present in this signal.

 

V5A is the reverb return

 

V7A and V7B are the reverb send drivers, and are in parallel, so there is a lot of current capable here. This is a 12AT7 tube.

 

On the high gain channel, the signal from V1A above hits V2A for another stage of gain, and then its off to V2B, for yet another stage of gain again.

 

Just like most amps, V1 and V2 are your primary gain and tone generation components.

 

After V2B comes V3A to drive the tone circuit, and this is sent off to the volume control for this side of the amp, the gain side. Remember, we had a stage of gain from V1A on the other circuit which fed the gain control on this side of the amp.

 

V6A and V6B are the vibrato send and return.

 

V4A and V4B is the phase inverter. This is the tube you'd notmally like to be matched. Its in its "proper place", close to the output tubes, but due to the amps layout, it is not the "highest V number" preamp tube as is the usual or most common case with most amps.

 

With the tube chart in the amp, you should be able to find all these 8 preamp tubes without too much trouble.

 

Regards,

[jazzcaster]

Hi Myles,

 

I am indebted for life for your help with the Pro Reverb tube section ID. I muddled through the schematic and managed to identify the reverb and vibrato, but was lost on the rest. I'm off to the races now. My only concern with this amp is that the vibrato channel has a lot of hiss, very audible. And the vibrato is not really audible at the 1/4 power setting. Is there a tube change I can make to quiet it down (and increase the "audibility on the 1/4 power setting?), or is this the nature of the beast? Does the Pro Reverb you are working on exhibit this problem? The hiss does not change with guitars (ie. it's not noisy single coils that are the culprit) and there is no problem on any of the other channels. My Peavey Delta Bluse 115 tremolo(vibrato) is much, much quieter, and thats what I'm using as my benchmark.

 

Thanks so much again Myles for your help. (I'm learning more on your forum page in the past few days than from any other source, ever).

[myles_rose]

Originally posted by OldManMetal:

Myles, I have a couple of questions I hope you can help me with. Both deal with tubes.

 

1. What tubes do you recommend for a Peavey Delta Blues 210 combo, used for everything from clean tones to rockin' blues tones?

 

2. What tubes do you recommend for a Mesa Boogie .50 Caliber + head used for mainly heavier tones?

 

Thanks for you help

OldManMetal,

 

I really cannot recommend a particular tube, as that is strictly personal taste. It also gets into a match of rise times and preamp tubes with power tubes, but rise times and the like depend on your playing style, attack, pick or no pick, heavy pick vs. light pick, and a ton of other factors.

 

I'd maybe have you start out by going to my website and reading some of the tube reviews and reports over there. That will get you in a ballpark or on some direction.

 

Regards,

[myles_rose]

Originally posted by Cornforduser:

Myles,

How great to know about the new GE 6L6!!!!

BTW, What would you do in my amp ?

Mullard ECC83 + GE 5751 + Mullard ECC83 (driver)

Mullard ECC83 + Mullard ECC83 + GE 5751 (driver)

What would be the effect of each ???

Cornforduser,

 

You amp .... hard question, as I do not know the individual characteristics of each of the tubes as far as rise times, output, etc. I'd need to look at each of these on a tracer as I do for my blueprinting comments.

 

Assuming all these are at the average factory spec though:

 

5751 in V1 will give you less front end gain and let the output stage play a larger part in your sound.

 

Tubes in V2 will have much less effect than those in V1, as V1 is your first gain stage.

 

In V3, a 5751 will give you a bit more clean headroom, but I'd prefer a 12AT7 in that position in your amp, as that is more of the characteristic sound of the Bassman circuit.

 

The Mullards in V1 and V2 will generally give you more detailed and complex sound, as these are very articulate tubes.

 

Regards,

[myles_rose]

Originally posted by jazzcaster:

Hi Myles,

 

I am indebted for life for your help with the Pro Reverb tube section ID. I muddled through the schematic and managed to identify the reverb and vibrato, but was lost on the rest. I'm off to the races now. My only concern with this amp is that the vibrato channel has a lot of hiss, very audible. And the vibrato is not really audible at the 1/4 power setting. Is there a tube change I can make to quiet it down (and increase the "audibility on the 1/4 power setting?), or is this the nature of the beast? Does the Pro Reverb you are working on exhibit this problem? The hiss does not change with guitars (ie. it's not noisy single coils that are the culprit) and there is no problem on any of the other channels. My Peavey Delta Bluse 115 tremolo(vibrato) is much, much quieter, and thats what I'm using as my benchmark.

 

Thanks so much again Myles for your help. (I'm learning more on your forum page in the past few days than from any other source, ever).

jazzcaster,

 

You're welcome for any help I gave.

 

Ah ... the vibrato culprit ....

 

These amps have a LOT of gain and a lot of high voltages running all over the place. With some of the interconnects, there is sometimes more hiss and hum than in some other amps. This is one of the reasons that preamp tubes in the Fender DeVille series have microphonic problems with one tube, while the same tube in a Black Face reissue will be fine as an example.

 

In your amp, V6 might be replaced with a better tube than the Russian Sovtek WA that it came with from the factory. I'd put a JAN NOS 12AX7A in there from somebody like KCA tubes. They are probably about $15.00. If you want to go with a new tube, try a Sovtek 12AX7LPS, as this may also help, or hit a Mesa Boogie store if there is one in your area and get one of their 12AX7's which are now the Electro Harmonix 12AX7EH, but they sell them for $10 retail, so its a pretty decent price. This is a driver position, so you don't need to go to the expense of any NOS or boutique high priced tubes.

 

Keep me informed and I'll try to step you through this. There is also a little cap trick that can be done to the socket for this tube, but for now, lets keep it stock.

 

These amps are not as quiet as some others, but that is due to the capability of very high gain and there is a lot going on inside of them. They are as quiet as most of today's high gain offerings, but most of today's high gain amps do not have the ability to get the clean sound of a Twin Reverb like your amp can get in addition to the gain it can get.

 

Regards,

[glzebub]

hello there myles.

could you spare just a sec for my problem,

 

i bought a few months ago after saving for a year a trace elliot C50 (owned by Gibson now btw), the manual says that four of the five ECC83's are used on clean and on overdrive, however when the overdrive boost (channel 3) is kicked on, a fifth preamp tube comes into the fray, another ECC 83 i believe, would it be possible to change this fifth tube to some sort of high gain tube so as to really emphasise the gain addition, cos it's a bit tame. something harder edged like a modern marshsall, it's still a bit vintage sounding just like the od without the boost, very little difference. i do love the normal drive channel but i would just love more of a change between theese two modes

one final thing, the output tubes are two Svetlana EL-34's, are these any good (i know nothing of this brand), would changing them improve the tone?

thank you very much.

[jazzcaster]

Thank-you for the suggestions on the Vibrato issue Myles. I'll try this and give you some feedback on it afterwards.

 

Cheers!

[myles_rose]

Originally posted by glzebub:

hello there myles.

could you spare just a sec for my problem,

 

i bought a few months ago after saving for a year a trace elliot C50 (owned by Gibson now btw), the manual says that four of the five ECC83's are used on clean and on overdrive, however when the overdrive boost (channel 3) is kicked on, a fifth preamp tube comes into the fray, another ECC 83 i believe, would it be possible to change this fifth tube to some sort of high gain tube so as to really emphasise the gain addition, cos it's a bit tame. something harder edged like a modern marshsall, it's still a bit vintage sounding just like the od without the boost, very little difference. i do love the normal drive channel but i would just love more of a change between theese two modes

one final thing, the output tubes are two Svetlana EL-34's, are these any good (i know nothing of this brand), would changing them improve the tone?

thank you very much.

glzebub,

 

The "fifth" tube is not what kicks on for extra gain. Only your first two preamp tubes are used for gain. Its more a matter of changing some voltages more than anything else after the first two gain stages, and a single ECC83 can provide two stages of gain depending on how the circuit is set up.

 

Your last preamp tube is generally you phase inverter and this is not a part of the gain structure.

 

ECC83's these days are made by Ei in some cases and by JJ in other cases. These tubes vary from 50% below spec to 40% above, and its all chance unless you have a way to measure and grade the preamp tubes.

 

If you want more gain, what you need to do is replace V1, as it feeds everything else, with an ECC83 (if you want to keep the same tonal characteristics and not make the amp darker or brighter). You have two options:

 

1. Call Bob at Eurotubes and have him hand pick you and ECC83 and tell him you want a really strong one.

 

2. Go to the Watford Valves website, and order an ECC83 from them, but tell them you want something in the 270-280 range. That will give you a LOT of gain.

 

Both these folks are on my website with their links.

 

On your Svetlana's .... some folks think these are some of the best EL-34's around. The are much better than the Sovteks which in turn are much better than any of the Chinese offerings.

 

If you want more mids, then you can go for a JJ E34L tube, which is an even stronger tube. These are also available as the E34LS tube from Groove Tubes with a slight difference.

 

For now, and to save some money, I'd just go for the preamp tube, as your Svetlana's are very strong and very nice tubes.

 

Hope this helped.

 

Regards,

[Griffinator]

Hey - one more question for you:

 

I've got a Fender Lead I that I just replaced hardware on - but I've discovered that the stock pickup is either too worn out or just not hot enough for my purposes.

 

Any recommendations on a pickup with more output, but still functions well in the coiltap/split 'bucker configuration? I love having that flexibility to go into "Strat" mode - and I want a pickup that will sound good split.

 

Cheers!

 

Griff

[hechtdavid]

Hi Myles,

 

I'm still looking for that perfect preamp tube set-up for my 1999 "Evil" Twin. I got a few JJ's (thanks Bob) and they really did the trick cleaning up the reverb and added some crunch (along with some grainy-ness) to the drive channel, but I'm still not happy with the clean sound. I've got 2 Groove Tube 7025's (Serbian origin) on the way. Where would you put 'em? V1(ch1), V2 (ch1 drive) or V3 (ch2) ? BTW, do you ever tour to the heartland? Would love to attend one of your amp clinics, but from Wisconsin to LA with a Twin is quite a haul. (Hell, even across town is a haul with this beast!)

 

Thanks - You're the BEST!

[Cornforduser]

Myles,

If the original Bassman preamp layout was :

12AY7 + 12AX7 + 12AX7 (driver) why people claim that a 12AT7 in the driver will make it more Bassman-ish???

Thanks.

[myles_rose]

Originally posted by Griffinator:

Hey - one more question for you:

 

I've got a Fender Lead I that I just replaced hardware on - but I've discovered that the stock pickup is either too worn out or just not hot enough for my purposes.

 

Any recommendations on a pickup with more output, but still functions well in the coiltap/split 'bucker configuration? I love having that flexibility to go into "Strat" mode - and I want a pickup that will sound good split.

 

Cheers!

 

Griff

Griffinator,

 

There are so many pickups out there that this is one of those questions where you may want to talk directly to the folks over at a play like Seymour Duncan.

 

This is all personal taste.

 

Regards,

[myles_rose]

Originally posted by hechtdavid:

Hi Myles,

 

I'm still looking for that perfect preamp tube set-up for my 1999 "Evil" Twin. I got a few JJ's (thanks Bob) and they really did the trick cleaning up the reverb and added some crunch (along with some grainy-ness) to the drive channel, but I'm still not happy with the clean sound. I've got 2 Groove Tube 7025's (Serbian origin) on the way. Where would you put 'em? V1(ch1), V2 (ch1 drive) or V3 (ch2) ? BTW, do you ever tour to the heartland? Would love to attend one of your amp clinics, but from Wisconsin to LA with a Twin is quite a haul. (Hell, even across town is a haul with this beast!)

 

Thanks - You're the BEST!

David,

 

The 7025's may be too bright for some tastes. I'd first try one of these in V2. If that does not do the trick, then put the tube back in V2 that was there, and try the 7025 in V1.

 

Your grainy nature may come from the output section now being driven in a different way than before if you have more or less gain going to the phase inverter.

 

Is your bias adjusted properly?

 

The 7025's are the "Fender sound", but newer Fender designs went to the 12AX7's rather than the 7025's.

 

I generally like a 12AX7 in V1 and V2 of these amps, rather than a JJ version, I'd prefer a JAN version of a USA tube (mostly still under $20), either GE's, Philips, or RCA.

 

The next choice on my list for these are the Sovtek 12AX7LPS or the 12AX7EH (Electro Harmonix) tubes, but be sure you know their output, as a tube that is too hot will add all sorts of noise and coarseness to the sound.

 

The best and safest bet on this attack, is to save time and get what you really want. What you want are tubes for V1 and V2, both 12AX7's, from Watford Valves, with a rating of 215 or so for V1 and 240 or so for V2 using their scale.

 

(For my clients, this would be a rating of 92 for the V1 tube and 108 for V2).

 

Regards,

[myles_rose]

Originally posted by Cornforduser:

Myles,

If the original Bassman preamp layout was :

12AY7 + 12AX7 + 12AX7 (driver) why people claim that a 12AT7 in the driver will make it more Bassman-ish???

Thanks.

Cornforduser,

 

I think some of the reason for folks saying this is a lack of understanding the various stages of change in the circuits and the change in tubes.

 

In the 6G6 circuit, a 7025 was used, but this was a USA tube that was a slightly lower output tube, that was stronger in construction, than the 12AX7's of the day back then. Today's non-US 7025's are quite a bit different than those of the past. Today, the gain characteristics of a 12AT7 are close to the 7025 in the past, and somebody probably used this, the rumor started, and everybody jumped on the bandwagon perhaps.

 

The 5E6-A used two 12AY7's in the first two positions and 6L6G's which are only about 19 watt tubes, less than later 26 watt 5881's and those are less than today's 6L6GC's, so this is really a very different citcuit.

 

The 5F6 is at times considered the "classic" Bassman circuit. This was the config you mentioned at the start of your writing. This did use the 12AX7 in the phase inverter position, but this amp also used a rectifier called an "83", which put out 450-0-450, and was very different than the later GZ34/5AR4 with its 550-0-550 output, so by using the modern rectifier, and then using a 12AT7 in the driver position, you can reduce the delta in the phase inverter portion of the circuit perhaps, or maybe some folks think it compensates in some way to make thing sound different, or .... maybe its just that folks are used to Fender using 12AT7 drivers a lot.

 

In the 5F6A circuit, Fender went to the GZ34 rectifier, which was perhaps the major change to some ways of thinking.

 

I would use what sounds the best to your own ears, as these tubes are all able to be changed to your heart's content. I like 12AY7's in V1 on these amps a lot, but a 12AX7 from somebody like Watford Valves with a rating of about 170, works really nicely too.

 

Regards,

[Ricksar]

Myles

 

I enjoy reading your thoughtful advice on various websites. Perhaps you can help me. I have a 1994 Gibson Les Paul Standard with Ernie Ball Super Slinky strings. I am looking for an amp (and effects?) which would give me some of the following amp tones: 1) Jimmy Page on "Led Zepplin 2", 2) Martin Barre on Jethro Tull's "Aqualung", 3) Leslie West on any old Mountain album, 4) Tony Iommi on the first "Black Sabbath" album, and/or 5) Jeff Healey.

 

Having traded in a Marshall Valvestate 8040 with which I was dissatisfied, I am left with a POD and a 1968 Fender Princeton Reverb.

 

If the process of finding the right tone becomes too time-consuming (I am a self-employed mid-40's-something, living in suburban Connecticut, 35 miles from NYC, who works long hours and plays so infrequently that I no longer have callouses on my fingers), I will probably buy a modeling amp (e.g., Vox Valvetronix or Line 6 Flextone?) just to have "something".

 

Can you provide me with any guidance before I take this "desperate" step (which is seemingly inconsistant with the pattern of your advice)? I just don't have the time to try lots of amps and the digital solution is beginning to look like an acceptable one. (Though the range of sounds that I am looking for is fairly narrow. I want that fat humbucking tone which makes it sound as though the pick is plucking against the pickup and causing the note to "wail"). Or might it be my guitar? Many thanks!

[glzebub]

thanks for the help myles, new valve on it's way.

very much appreciated.

[hechtdavid]

Originally posted by myles111:

Originally posted by hechtdavid:

Hi Myles,

 

I'm still looking for that perfect preamp tube set-up for my 1999 "Evil" Twin. I got a few JJ's (thanks Bob) and they really did the trick cleaning up the reverb and added some crunch (along with some grainy-ness) to the drive channel, but I'm still not happy with the clean sound. I've got 2 Groove Tube 7025's (Serbian origin) on the way. Where would you put 'em? V1(ch1), V2 (ch1 drive) or V3 (ch2) ? BTW, do you ever tour to the heartland? Would love to attend one of your amp clinics, but from Wisconsin to LA with a Twin is quite a haul. (Hell, even across town is a haul with this beast!)

 

Thanks - You're the BEST!

David,

 

The 7025's may be too bright for some tastes. I'd first try one of these in V2. If that does not do the trick, then put the tube back in V2 that was there, and try the 7025 in V1.

 

Your grainy nature may come from the output section now being driven in a different way than before if you have more or less gain going to the phase inverter.

 

Is your bias adjusted properly?

 

The 7025's are the "Fender sound", but newer Fender designs went to the 12AX7's rather than the 7025's.

 

I generally like a 12AX7 in V1 and V2 of these amps, rather than a JJ version, I'd prefer a JAN version of a USA tube (mostly still under $20), either GE's, Philips, or RCA.

 

The next choice on my list for these are the Sovtek 12AX7LPS or the 12AX7EH (Electro Harmonix) tubes, but be sure you know their output, as a tube that is too hot will add all sorts of noise and coarseness to the sound.

 

The best and safest bet on this attack, is to save time and get what you really want. What you want are tubes for V1 and V2, both 12AX7's, from Watford Valves, with a rating of 215 or so for V1 and 240 or so for V2 using their scale.

 

(For my clients, this would be a rating of 92 for the V1 tube and 108 for V2).

 

Regards,

Hi Myles,

 

Is there anyplace in the US that will "rate" these tubes? For your clients, what do the numbers 92 and 108 refer to? I'm hoping to get something domestically..

 

Thanks again,

 

David

[myles_rose]

Originally posted by Ricksar:

Myles

 

I enjoy reading your thoughtful advice on various websites. Perhaps you can help me. I have a 1994 Gibson Les Paul Standard with Ernie Ball Super Slinky strings. I am looking for an amp (and effects?) which would give me some of the following amp tones: 1) Jimmy Page on "Led Zepplin 2", 2) Martin Barre on Jethro Tull's "Aqualung", 3) Leslie West on any old Mountain album, 4) Tony Iommi on the first "Black Sabbath" album, and/or 5) Jeff Healey.

 

Having traded in a Marshall Valvestate 8040 with which I was dissatisfied, I am left with a POD and a 1968 Fender Princeton Reverb.

 

If the process of finding the right tone becomes too time-consuming (I am a self-employed mid-40's-something, living in suburban Connecticut, 35 miles from NYC, who works long hours and plays so infrequently that I no longer have callouses on my fingers), I will probably buy a modeling amp (e.g., Vox Valvetronix or Line 6 Flextone?) just to have "something".

 

Can you provide me with any guidance before I take this "desperate" step (which is seemingly inconsistant with the pattern of your advice)? I just don't have the time to try lots of amps and the digital solution is beginning to look like an acceptable one. (Though the range of sounds that I am looking for is fairly narrow. I want that fat humbucking tone which makes it sound as though the pick is plucking against the pickup and causing the note to "wail"). Or might it be my guitar? Many thanks!

Ricksar,

 

If you are going to play in your house and just want to fool around a bit, then any of the modeling amps are fine. Its mostly a matter of features and price in respect to them.

 

If you are ever going to play in a live situation, then for the Mountain sound, there is really only one choice, and that is to find a mid 60's vintage Sunn amps, as what lined the stages at Woodstock, along with the Fender's, Marshalls, and Acoustic 360's.

 

A four input Marshall will get you most of the other sounds associated with what you mention, but these were driven very hard.

 

When you say you are "left with" the 68 Princeton Reverb, consider yourself fortunate. This is a great amp, and if you get a real tube type distortion pedal and front end that amp using input #2, which will give the front end of the Fender more headroom by about 6db, you will be in business with a great sound at rational levels.

 

Make sure your Fender amp is properly biased, and has the proper tube compliment. If they are original tubes, they are probably long overdue for a change, and this will make a very big difference.

 

Regards,

[Guitarzan]

hi Myles, i am the guy with the digitech rp14d looking to replace the tube, i can get these tubes:

12ax7a jan-philips ecg usa

12ax7 canadian marconi cmc

usa ecg philips ..with blue silk screened lettering , marked 12ax7,ecc83,7025 on the box and the tube

these are all N.O.S tubes

how do you rate these for tone and gain as well as microphonics? in a multieffect unit is microphonics an issue?

[MesaUser]

Hello Myles, How hard is it to blow a tranny? My recto(3 channel) has went through a few accidents, as in having the cab unplugged while its on, plugging the cab into the wrong spkr jack. I remember someone sayin that newer amps have a built in load type thing, and I remember the recto manual didnt say anything about damaging the tranny. So does my amp have something to protect from this. It still sounds fine to me.

[MesaUser]

I accidentally pressed refresh or back on my browser...Sorry Myles.

[myles_rose]

Originally posted by MesaUser:

Hello Myles, How hard is it to blow a tranny? My recto(3 channel) has went through a few accidents, as in having the cab unplugged while its on, plugging the cab into the wrong spkr jack. I remember someone sayin that newer amps have a built in load type thing, and I remember the recto manual didnt say anything about damaging the tranny. So does my amp have something to protect from this. It still sounds fine to me.

MesaUser,

 

If you amp is working fine, and you did not smell smoke, you are probably okay.

 

Some of today's amps have a shorting jack in the speaker output from the amp, so when nothing is inserted, there is no B+ to the power section. This was always a cool feature of Rivera amps, but not in a lot of Mesa amps, or others.

 

Even with a shorting jack, running an amp at the wrong load, will in time (sometimes a very short time), cause tube failure or output transformer failure.

 

It sounds though, that you are fine.

 

Amps with older transformers that have seen years of abuse can die in a flash, so its best, even with new amps, to be a bit careful.

 

Regards,

[jazzcaster]

Hi Myles,

 

Just a short update on my Pro Reverb vibrato problem (Lots of noise, not audible at 1/4 power setting). It was, in fact, a defective tube (V6). I replaced the stock Sovtek with a Jan GE 12AX7WA and its fine....quiet, and works great at 1/4 power setting. I didn't really suspect a bad tube because the amp was brand new. Live and learn.....thank-you for your help. How are you making out with your customers Pro Reverb that you've been working on?

 

Best regards!