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Hi Myles, I just got a Line 6 Spider Valve 112 amp, and I'm told I should replace the tubes, which are apparently of a disreputable Chinese make. Got any suggestions for 12AX7s and 6L6s that would work better in that amp than some others?

Always remember that you are unique. Just like everyone else.

 

 

 

 

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Hi Myles, I just got a Line 6 Spider Valve 112 amp, and I'm told I should replace the tubes, which are apparently of a disreputable Chinese make. Got any suggestions for 12AX7s and 6L6s that would work better in that amp than some others?

 

Actually .... save your money and go out for a nice meal.

 

The Chinese 12AX7s are some of the best on the market today (and have actually been for years. They are smooth and linear. They are also very reliable.

 

As far as the output section .... those 6L6s ..... The Line 6 stuff develops it's tone from many aspects of the overall circuit design and one can actually use any reliable 6L6 in the amp. Unlike a simple, basic, traditional amp of the past, these amps have a much wider tonal palette and what is desired in tube characteristics is neutrality.

 

I have many friends who are Mesa Boogie amp owners and users. When they see I used Sovtek 5881 WXTs (just a generic 6L6 that is stuck with a 5881 printing in it by Sovtek) in my own Mk. 1, they comment at times .... "with the great tubes you have available why do you use one of the most generic and cheapest tubes around"? Same reason as I gave you for the Spyder Valve. The Mesa gets it's tonal character from the front end, not from the output stage. It is a pretty basic amp, actually, much less complex than the Line 6 Spyder Valve. Then again, almost have a century and a lot of technology separates the two designs.

 

So .... in the end .... keep your money and enjoy your amp. The tubes in the amp are about as good as it gets ... linear and reliable.

 

Happy playing :)

 

Myles S. Rose

www.guitaramplifierblueprinting.com

www.la-economy.blogspot.com

www.facebook.com/mylesr

www.twitter.com/myles111us

 

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I'm in the market for a new amp. I just heard an amp I really like the sound of.

 

The power tubes are two 6973s. Would this be a risky purchase. I've never had an amp with these tube. I wouldn't want to buy and amp and not be able to get replacement tubes in a few years.

"It doesn't have to be difficult to be cool" - Mitch Towne

 

"A great musician can bring tears to your eyes!!!

So can a auto Mechanic." - Stokes Hunt

 

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  • 5 months later...
I have a silverface Fender Vibrolux Reverb I think its a 1973 anyway when I turn on the vibrato it makes a thub thub thub heartbeat noise but only if the intensity is 2 to 9 at 10 it works fine. Any idea about where to start. I know how to work on amps but not sure where the problem could be as my knowledge is limited as far as circuit design goes I think it is the AA964 layout but will have to pull the chassis to be sure. I had the amp rebuilt several years ago and I don't think it did that before. It is pretty annoying if I don't leave the intensity all the way up but other than that it seems to work great.
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Hum is that the 7025 which is 4th from the right looking at the back of the amp or the 12AT7? The 7025 was bad and I replaced it. Before I replaced it the amp was going crazy when the vibrato was on.

 

That tube was the original as the one installed during the rebuild was bad. It was all frosty looking and the vibrato channel did not work at all if I remember correctly.

 

I need to order some new Preamp tubes anyway as I have several tube amps as well as two I built from scratch.

 

I don't get why it goes away at full intensity.

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  • 5 months later...

Greetings Myles;

 

I've a Carvin AG-300 amp that has an intermittent and loud as hell white noise that comes and goes. It's level is controlled by the master volume, not affected by the channel preamp volumes, so I assume it's in the power amp section. Re-boot the amp, and it's gone until it comes back again. Carvin has gone tits-up and doesn't repair this amp anymore.

 

I'm pretty sure I'm not the only one with this situation, and expect it will be outside of my normal DIY comfort zone...but who knows? I can remove the electronics plate from the cabinet for easy mailing. Got a repair guy/gal in mind or other ideas on how to proceed?

 

Worst case scenario is that I find the specs for the crossover in the passive version of that cab and swap those bits in. Shame that the crossover is built into the plate--I had hoped it would be as easy as soldering up an input jack.

 

Best,

Paul K

Things are just the way they are, and they're only going to get worse.

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  • 2 weeks later...
Wondering from a reliability standpoint how you feel about running keyboards (wide range, possibly hot signal) through an all tube guitar amp. It's been done by keyboard players dating back to Deep Purple using Marshall amps. Not talking about the speaker cabinets - I'm well versed on the physics and design of speakers and enclosures. I have an electrical engineering background as well, but all solid state, almost nothing on Tube amps. This would primarily be for lead synth, but could possibly get into some deeper bass frequencies, and since it will be a pure analog synth, voltages generated could spike fairly high. Just wondering if tube preamp stages are well suited to handle this without shortening life, or if it would be better to possibly limit the frequency range, or at least maybe put a compressor/limiter inline. If it matters, this particular amp uses (2) 12AX7 tubes in the preamp stage, and (2) GE 6AQ5 Beam Power tubes (Class A/B) in the output stage - only 18W but I don't need a lot of power for this application. For what I'm looking at doing, think Derek Sherinian (Dream Theater, Sons of Apollo). Just wondering about longevity.

Dan

 

Acoustic/Electric stringed instruments ranging from 4 to 230 strings, hammered, picked, fingered, slapped, and plucked. Analog and Digital Electronic instruments, reeds, and throat/mouth.

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Wondering from a reliability standpoint how you feel about running keyboards (wide range, possibly hot signal) through an all tube guitar amp. It's been done by keyboard players dating back to Deep Purple using Marshall amps. Not talking about the speaker cabinets - I'm well versed on the physics and design of speakers and enclosures. I have an electrical engineering background as well, but all solid state, almost nothing on Tube amps. This would primarily be for lead synth, but could possibly get into some deeper bass frequencies, and since it will be a pure analog synth, voltages generated could spike fairly high. Just wondering if tube preamp stages are well suited to handle this without shortening life, or if it would be better to possibly limit the frequency range, or at least maybe put a compressor/limiter inline. If it matters, this particular amp uses (2) 12AX7 tubes in the preamp stage, and (2) GE 6AQ5 Beam Power tubes (Class A/B) in the output stage - only 18W but I don't need a lot of power for this application. For what I'm looking at doing, think Derek Sherinian (Dream Theater, Sons of Apollo). Just wondering about longevity.

 

Dan,

 

No reliability issues at all. If the output from the keyboard is too hot the tube in the first gain stage will compress and sound pretty awful (but that may be an effect on it's own :) ) but you can just turn down the keyboard output or pad it prior to the guitar amp input.

 

 

Myles S. Rose

www.guitaramplifierblueprinting.com

www.la-economy.blogspot.com

www.facebook.com/mylesr

www.twitter.com/myles111us

 

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  • 2 weeks later...

Thanks, another unrelated question....

 

We got rained out in an outdoor gig about a month ago. I had my guitar on a stand under a tarp but apparently at some point somebody tripped in the cord and knocked it over and I found it laying face up on the ground completely soaked. I tried it but it was extremely muddy and weak output. I was hoping it would dry out and work again, but it's been about a month and exactly the same. Note: it's an explorer with 2 SD humbuckers.

 

So time to open it up and trace down the problem. First, same symptoms on both pickups, so either both suffered the same fate or it's something else - the muffled sound would suggest to me tone poor capacitor, but the level is also extremely weak suggesting maybe some sort of partial short - I would think would clear after drying out unless it's corrosion,

 

So I have a Fluke DMM and a BK Precision LCR meter similar to This. I just want to make sure I'm in the right track with my troubleshooting.

 

I figure for each pickup I can check DC resistance and coil inductance and compare to the Seymour Duncan specs and look for deviation, as well as maybe just bypass the volume/tone pots and look for a normal output direct from each pickup. If they check out, pots are easy enough to check with a DMM checking resistance. The capacitor in the tone pot can be checked with the LCR and the pickup switch and Jack can be checked with simple continuity. Anything to add?

Dan

 

Acoustic/Electric stringed instruments ranging from 4 to 230 strings, hammered, picked, fingered, slapped, and plucked. Analog and Digital Electronic instruments, reeds, and throat/mouth.

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  • 1 month later...

Hi Myles,

 

I am looking for a small amp that I can carry around when I teach. I see great review of Roland - CUBE-10GX on the internet. Could you tell me your opinion. The quality of sounds does not really matter, but I am looking for something that last long. If you have any other suggestions with similar size amp, please kindly let me know.

 

Thank you so much for your help in advance.

 

Kenji

 

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Hi Myles,

 

I am looking for a small amp that I can carry around when I teach. I see great review of Roland - CUBE-10GX on the internet. Could you tell me your opinion. The quality of sounds does not really matter, but I am looking for something that last long. If you have any other suggestions with similar size amp, please kindly let me know.

 

Thank you so much for your help in advance.

 

Kenji13,

 

When it comes to small amps, Roland has been making them for longer than anybody else. Sure, there were fun toys like the original Pignose amps, but Roland stuff has always been full featured stuff with the emphasis on playing, not novelty.

 

Their products are well engineered and very reliable. I have owned a Roland Cube 60 since the eighties. It never failed. It is being used in Seattle by a bass player for small gigs on a continual basis .... with the original speaker no less.

 

There are many amps of these types out there but Roland sort of set the stage for all others. Their Micro Cube stuff have been used on more recordings for high gain stuff than I can being to count.

 

Happy playing .... for a toss and go amp to teach their lineup is pretty darn cool.

 

Myles

 

Myles S. Rose

www.guitaramplifierblueprinting.com

www.la-economy.blogspot.com

www.facebook.com/mylesr

www.twitter.com/myles111us

 

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  • 2 weeks later...
I have a peavey kb 300 solid state amp that got left turned on over night , next day turned it off let it cool down a few hours . Turned it back on power light comes on ,but amp is dead , where should I start to look ,thanks Myles any ideas

 

It's amp tech time. It could be too many things to check if just "shotgunning". They are a pretty nice keyboard amp as a side note, easy to get around and use for local gigs. Good luck. If you are in New York or can ship it I'd go with Blackie. Link

 

 

Myles S. Rose

www.guitaramplifierblueprinting.com

www.la-economy.blogspot.com

www.facebook.com/mylesr

www.twitter.com/myles111us

 

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  • 6 months later...

Myles- please forgive a possibly absurd question, but . . .

 

I have a vague recollection of a friend's Guitar Amp, back in '68/69, with a Surf effect, essentially a White Noise effect that sounded like Surf behind the Guitar. I'm not thinking of a classic Reverb or Tremolo unit, we were familiar with those, and I'm sure no one had a built-in Phaser/Uni-Vibe effect at the time. (I do recall a built-in Phaser on my old Peavey Deuce, but that was much later.)

 

Any help or guidance would be appreciated. It is possible that I have something mixed up in my memory, but this was a good friend, and the only 14-year-old in my group of friends whose parents bought him a real Strat and Fender Amp as his starter gear, so it made an impression: the rest of us were making do with whatever we could find at Lafayette Radio Electronics, or the like.

 

Many thanks!

"Monsters are real, and Ghosts are real too. They live inside us, and sometimes, they win." Stephen King

 

http://www.novparolo.com

 

https://thewinstonpsmithproject.bandcamp.com

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  • 2 weeks later...

Hi Myles,

I just purchased a used 60 watt Mk 3 Boogie on Ebay, and I'm very jazzed about it. It should arrive by April 16th, and in the meantime, I'm getting a set of tubes. I have the 6L6s, a matched pair of Boogie STR 440s, and the SPAX7. I am looking at the regular 12AX7s, and I wondered if you think a set of Tung-Sol 12AX7s, specifically ( THESE would work well in that amp.

Always remember that you are unique. Just like everyone else.

 

 

 

 

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Hi Myles,

I just purchased a used 60 watt Mk 3 Boogie on Ebay, and I'm very jazzed about it. It should arrive by April 16th, and in the meantime, I'm getting a set of tubes. I have the 6L6s, a matched pair of Boogie STR 440s, and the SPAX7. I am looking at the regular 12AX7s, and I wondered if you think a set of Tung-Sol 12AX7s, specifically ( THESE would work well in that amp.

 

Congrats on the new amp. These are pretty nice, not too heavy and easy to toss in the car.

 

These amps are pretty non-critical on tubes. The Mesa output tubes are fine. The amp gets their tone from the front end more than the back end so any good 6L6 type works great. The STR440 is a nice sturdy tube.

 

As far as preamp tubes .... play the amp for a while before you change stuff. The Tung Sols branded tubes by Sovtek are fine but the tubes in the amp now are probably fine. I'd just play the amp for a while and down the road you can grab a nice medium plate NOS 12AX7 for V1 and a good long plate, proper spec tube for the phase inverter.

 

As a side note, the folks selling those tubes on ebay are good folks.

 

Happy playing ;)

 

Myles S. Rose

www.guitaramplifierblueprinting.com

www.la-economy.blogspot.com

www.facebook.com/mylesr

www.twitter.com/myles111us

 

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Thanks Myles. My first Boogie was a 60 watt like this one, plain jane amp with no graphic or reverb, and I haven't felt entirely comfortable with an amp since I had to part with it.

 

I had a second Boogie, another mark 3, but it was the full-dress 100 watter with graphic, reverb and the Simul-class setup. I expected it to pretty much fall right in where the 60 watter did, and it was a good amp, but it was never quite the same.

 

Here's hoping this one will be more like my original.

 

Always remember that you are unique. Just like everyone else.

 

 

 

 

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  • 2 weeks later...
Another question; What is the difference between a 6L6GC and a 6L6WXT? I found a matched pair of Sovtek WXTs on Ebay for about $30. What little I've been able to find out says they are designed for higher voltage, and I'm just curious about them.

Always remember that you are unique. Just like everyone else.

 

 

 

 

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Another question; What is the difference between a 6L6GC and a 6L6WXT? I found a matched pair of Sovtek WXTs on Ebay for about $30. What little I've been able to find out says they are designed for higher voltage, and I'm just curious about them.

 

Today, all those descriptions are nonsense. As far as higher voltages, none of today's production tubes are capable of being reliable anywhere close to original design spec.

 

Myles S. Rose

www.guitaramplifierblueprinting.com

www.la-economy.blogspot.com

www.facebook.com/mylesr

www.twitter.com/myles111us

 

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  • 1 month later...
  • 2 months later...

Howdy, Myles!

 

I recently was gifted an old Oliver 120B Bass amp. While it works, it definitely needed some cleaning up. I also got some new 6L6 power tubes for it. The preamp uses 2 6EU7 tubes. These are a little harder to come buy. Any recommendations of brands/sites to use? to avoid? I know you can't substitute 12AX7 tubes, but is there another acceptable substitute without having to re-wire or re-bias the amp?

 

Appreciate your knowledge & guidance!

"Am I enough of a freak to be worth paying to see?"- Separated Out (Marillion)

NEW band Old band

 

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  • 6 months later...

I have a Fender Vibrolux Reverb from about 1970 or so. It had been unused for quite some time and I decided to fire it up today. It made a terrible noise for about ten minutes after I hit the standby switch. The power switch had been on for about 10 minutes before I hit the standby. After a while and several on off with the reverb and vibrato it cleared up. Any ideas ? Maybe a tube going out? One of the tubes is original as the new one from the last rebuild blew out. It is probably micro-phonic to some extent.

 

I don't really want to open it up without some idea of what to look for :blush:

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