I Got My First Tube Amp! Boy, Do I Feel Pathetic...

[stratcat2k]

Hi Y'All -

I'm hoping that I can get some help from the friends in the Forum! After 20 odd years of playing guitar, I have finally been able to acquire an all tube amp, a Peavey 6505+ 112 combo amp. All my life I've used solid state (for the past 2 or 3 years, I've used a Fender Frontman 2x10 as a cab with a Line 6 PODxt bean), mostly for economic reasons - where I live, all-tube amps are very expensive, due to import duties and taxes and such. However, the opportunity came up to purchase this amp and although it is a more "metal" amp than what I actually play (I play more classic rock and 80's hair metal), I just couldn't pass up the opportunity to buy it when the chance came up; it was that good of a deal (also the rhythm channel on the crunch setting sounds great!).

 

Anyway, to make a long story short, even after years of reading fine publications such as GP, I came to the crushing realization that basically I know SQUAT about tube amps. I'm looking for books on the general care of tube amps, but I need some guidance right now. Can you guys give me pointers as to the general care and maintenance of all-tube amps, from the proper way to turn them on and off (heck, I should know this, but still... better too safe than too sorry), all the way to general care of the tubes, changing the tubes when they're worn out, how do I know they're worn out, changing the type of tubes (i.e. the 6L6's for EL84's or whatnot and if so, what might be a good subsitute for my style of music), and/ or anything else I should know? I know I come off as incredibly ignorant, but I'd rather ask the experts (you guys), than to start fiddling around and possibly damaging my investment, leading to expensive repairs. Also, what books are out there that you could recommend in relation to tube amp repair and maintenance?

 

Thanks!!

Andy.

 

[Bartholomew]

I had a tweed Peavey Delta Blues amp with a 15 inch speaker and used it for approx 10 years - never did anything to it and sold it with the original tubes still inside - one of the best amps I ever had.

 

Also have a 1968 siverface Fender twin reverb in my living room - last time I did anything to it was a tube change probably around 1971 but it farts at any volume over 4 and if I could carry it I would have a tech do work but it never leaves my house anyways. Guess it needs capacitors and tubes maybe new speakers but it's fine at low volume.

 

My attitude is that I never do work unless I have to but I guess you should change your tubes when you see blue gas inside or depending on how much use you give it - other people here have more knowledge about these things than I do.

[desertbluesman]

I can't help you much. I always use all tube amps, When I change tubes I talk to the tube sales folks. Usually Bob at Eurotubes and I have learned to BIAS the power tubes with the videos on Eurotubes site.

 

You should let the tubes warm up for a few minutes before playing. Perhaps 10-20 minutes. Which I never do I just turn on the amp and play after it warms up for several minutes. But I have read this on this forum.

[Caevan O’Shite]

That amp should also be great for a lot of "Classic Rock" sounds.

 

Turn the amp on, but on "Standby" for a while, to let the heater-filaments warm-up the tubes before voltage is applied to 'em. When powering-down, put it on standby first, and then turn off the power.

 

 

Turn the amp up a little louder than you actually intend to be, and begin with the guitar's volume-knob turned down enough to give you clean tones, along with your picking "touch"; bring up the guitar's volume-knob and pick harder for more overdriven tones, and bring it up even more for more gainy, distorted and compressed "lead" tones. Learn to "play the amp", cultivate your "touch". You'll be dripping in Classic Rock Tone Glory if you master this approach.

 

 

If you need new tubes, I highly, highly recommend contacting and ordering from Doug's Tubes.

 

 

Even if you're not planning on doing any work on your amp yourself, I highly recommend:

 

 

http://www.stewmac.com/catalog/images_1sm/1191_1sm.jpg

 

* How To Service Your Own Tube Amp, by Tom Mitchell. (Media Concepts, Norwalk, CA) It may sometimes still be bought with a companion video- highly recommended. Includes some very useful troubleshooting "flow-charts", mods and tweaking, some schematics, and a lot of useful reference info not always found elsewhere.

 

 

Go the "Feel free to ask Myles"-thread, feel free to ask him anything tube-amp related, and follow the link in his signature-line to his Guitar Amplifier Blueprinting 'site and read his Tube Primers.

[Gabriel E.]

As previously mentioned, allow it to warm up for around 30 seconds before turning the amp from "standby" to "play/on". Other than that, there's not much you need to do.

 

Capacitors should be replaced every 15 years or so by a service tech. Power tubes (the big ones) should be replaced more frequently. Every year or so if you are gigging constantly. Every 3-5 years if you are a casual/garage/bedroom player. Preamp tubes (the little ones) only need to be replaced when they go bad.

 

Have fun!

[Caevan O’Shite]

If in time you happen to have problems with preamp-tubes developing microphonic sensitivity and making sympathetic ringing, whistling or squealing noises, before replacing said preamp-tubes, this can sometimes be temporarily fixed by careful placement of "Hal-O" tube-dampers on their glass to damp-out the vibration.

 

I put three Hal-O tube-dampers on tubes in my amp several years ago when I started having whistling, ringing problems with V1, V2 and V3, and they worked like a charm; those three preamp-tubes are still going strong, and not making noises... Now, this took a little trial-and-error to find just where to place the dampers, but the results have been excellent, saving me the purchase of three tubes and extending the useful life of the tubes I'd put in there...

 

 

If and when you eventually replace the output-tubes, stick with the basic type (6L6's/5881's for your amp, if I recall correctly), and:

 

(A) get a matched set- in your case, a matched duet, right?

 

(B) also replace the phase-inverter, and replace it with a "matched" or "balanced" Phase-Inverter, aka an MPI; the Output-Tubes and the Phase-Inverter tube work and wear-out together as a team, and having a Phase-Inverter tube that has been tested and found to have closely similar characteristics between its two internal triodes (that the signal is split between to drive the output-tubes) is very beneficial to healthy, consistent tone and output. A poorly balanced/unmatched Phase-Inverter can give the perceived impression that your guitar's fretboard has "dead-spots" due to phase-cancellations, and generally weak tone and performance all-around.

 

(The Phase-Inverter tube will be the small/preamp-type tube closest to the output-tubes, usually to their immediate left or right, most often a 12AT7 or 12AX7.)

 

 

Now, when you do replace the output-tubes, have the amp turned off and unplugged, and allow the tubes to cool down if the amp's been on- do NOT burn your fingers! Remove or loosen any tube-retainers, and carefully, gently wiggle and pull the tubes out of their sockets one by one. There is a key-way and the pin-outs in the socket only allow the tubes to go in one way. Use a Sharpie Marker to make an index-line for easier removal and replacement in the future- their ink stands up to the heat and they'll write on glass- and also mark the date and respective socket ("V5, V6, etc.).

 

I believe that your amp requires 6L6/5881 type output-tubes; if so, stick with those, don't worry about whether you should mod it to run EL34's, etc. You're a long ways off from having to worry about such cork-sniffing!

 

If your amp allows for switching from 6L6's to EL34's, such as with a switch on the back-panel, then by all means, try them out if you want; look into whether your amp has an adjustable "fixed" bias-control inside, and if so, have a qualified, experienced tech adjust the bias for you the first time you change the output-tubes, whether they're 6L6's/5881's or EL34's.

 

Don't accidentally confuse EL34's with EL84's when buying tubes- the former are large, eight-pin, higher-power tubes often found in Marshalls, while the latter are small-bottle nine-pin lower-power tubes, often found in Voxes and many smaller 30 watt and under Peaveys, Fenders, Carvins, etc. They will not even remotely fit in the same sockets nor work within the same specific circuit requirements.

[Gifthorse]

I really am ignorant about any electronics topic. I know nothing about it.

 

BUT, I have learned from people who do know that Peavey amps have low plate voltage. What this means is that tubes almost never need replacement. I think this is true too.

 

When I had my Peavey VTM (which I LOVED--my fav Peavey amp), I never replaced the tubes and it still sounded the same. I even dropped the head once--it still worked perfect.

 

This is a good thing for someone who wants a highly reliable amp. But if you want to get the power tubes to kick in and add girth and compression--unfortunately that isn't going to happen.

 

I do think 5150's are good amps, and versatile for rock and metal.

 

I know Eddie designed it using a VTM and his old Marshall. He basically liked the VTM but wanted a more compressed tone.

 

I LOVE VTM's as I have mentioned alot in this forum. The most interesting amp Peavey ever made in my opinion, and it sounded GREAT micd live or in the studio.

 

But 5150's sound great live too if they are eq'd properly. They have a ton of girth in the mix.

[Chad Thorne]

Enjoy that new tube amp!

 

Candidly acknowledging that one does not know something and seeking the information is the furthest thing from pathetic in the world. Good on yer.

[p90jr]

The Guitar Amp Handbook

 

and

 

The Guitar Amplifier Player's Guide

 

&

 

The Guitar Amplifier Player's Troubleshooting Guide

 

 

are all good...