picker

Very cool, thanx much. I'll put the order in tonight. Myles, the tubes arrived last week, and they made little or no noticeable difference. So, I decided to switch the preamp tubes(all 12AX7, by the way) around to see what would happen, and that made a big difference. With them re-arranged in one sequence, the volume dropped to almost nothing. In another sequence, the amp went back the grungy, unclean sound it had developed. In a third sequence, the amp sounded like it did before the trouble started. I got back in touch with Joe Naylor at Reverend, and told him what I had discovered with the tube switching. He had me send the amp back to them for a look-see. I gotta say that the folks at Reverend have been marvelous. I think Naylor is the head guy, and he's dealt with me personally everytime I have called or emailed them. So, I am currently in "wait & see" mode. I'll let you know what the final result is. In any event, thank you for taking care of the new tubes at your end, and for all the information you gave me.

I have never had this much trouble with an amp before. I'm about ready to trade the bloody thing for a modeling amp. And I hate modeling amps.

Myles, I had a weird thought. Since the tech rebiased the amp with possibly damaged tubes, would the tubes being damaged affect the biasing enough that the amp wouldn't be biased right for undamaged tubes? Wow, I'm dizzy from saying that...

Very cool, thanx much. I'll put the order in tonight.

Is there any way to order a set of 6V6Cs specifically with a "6" rating direct from GT? I went out to the website, and they only offer ranges (1-3, 4-7, & 8-10). Paying $40 and shipping is a better than spending another $40 on re-biasing AND paying for a new set of tubes, too.

Well, the amp sounded great after the GTs were installed for a lot longer than 15 minutes. I wouldn't know if it was underbiased or not. All I know is that it used to sound good, and for some it reason, it stopped sounding good. And, I paid close to $40 to have the amp biased for a $30 set of tubes that I now find out may have been trashed before the biasing, and the dumb butt tech who did it either didn't know, or didn't give a rat. Dirty word dirty word, cuss cuss cuss! If you are anywhere near me I'd be happy to look at the amp for free. It's a long stump from KC to LA., but thanx for the offer. Since the amp is biased for 6V6Cs preformance rated 6, if I got another set of the same tubes, would the biasing still be right?

Well, the amp sounded great after the GTs were installed for a lot longer than 15 minutes. I wouldn't know if it was underbiased or not. All I know is that it used to sound good, and for some it reason, it stopped sounding good. And, I paid close to $40 to have the amp biased for a $30 set of tubes that I now find out may have been trashed before the biasing, and the dumb butt tech who did it either didn't know, or didn't give a rat. Dirty word dirty word, cuss cuss cuss!

Myles, I spoke with Joe Naylor again, and he suggested trying different power tubes to see if they are the problem. IS there any way you can think of that a set of GT 6V6Cs performance rated at 6 would go south in a Goblin, maybe if the amp weren't biased right for them and you ran it that way for a while?

Somebody needs to look at the voltages across the circuit. Which circuit? If I tell a tech "look at the voltages across the circuit" will he know what I mean?

Okay, Myles, here's the skinny. I got that Reverend Goblin I have been writing to you about sort of fixed. I got a replacement reverb tank from Joe Naylor, installed it, and the reverb came back. And, I thought I had the distortion problem fixed, by replacing the 5751 I had in it with a 12AX7. I figured the 5751 I had bought for it went south or something. But, no matter how low I set the input volume and how high I set the master volume, it never really gets clean. I would just say that it's not a sound that's in that amp, but it used to be there. It would get very clean and pretty loud at the same time, right after I replaced the EH 6V6s that it came with and put in the GT 6V6s. The amp was rebiased for the GTs, and the reverb tank replaced, as I said before. Can you suggest anything else, or should I just try to sell the silly thing?

Myles, IF you remember, I have been having issues with my Reverned Goblin. I bought a set of GT 6V6 after one of the Electro Harmonix's it came with cracked. They worked fine for a while, but then the amp started distorting at any level and/or setting. I toolk it back and the tech at the stare sid the amp needed to be re-biased for the new GT tubes. Well, I paid for that to be done, and I got the amp back. First off, when I plugged it in and turned it on, the amp didn't work. The 2nd pre-amp tube looked milky around the top, and when I pulled it out, it was cracked. So, I replaced it and turned the amp on again. It worked, but the same problem it had before is still there; it distorts at any setting. Now, the reverb doesn't work, although there is a slight increase in volume when the reverb knob is turned all the way up. I checked the reverb tube(I think; it's the 12AX7 behind all the other tubes, right?), and it seems fine. Any ideas what might be wrong?

This could be many things. If you know the tubes are good via a proper tube tester then it looks like it is time for the amp to see a tech's bench. It could be too many things to guess here without having the amp on a bench. I took the amp back to the store, and their tech guy says he thinks the Groove Tubes I put in to replace the Electro Harmonix tubes it came with are the wrong bias, and that the amp needs to be biased. Now, when I replaced the tubes, there was no problem. The distortion developed a while after I changed them out, not immediately, which I would have thought would be the case if the bias was wrong. And, I was under the impression that a matched set of replacement tubes wouldn't require re-biasing. I asked what biasing the amp for the tubes would cost, and they told me $30, if the tubes didn't need replacing, more if they did, of course. Am I being hosed or not? If they are the SAME type tubes at the SAME rating AND the amp was biased properly in the first place (and most factory amps are not from my experience) then it is plug and play. Well the GTs were GT6V6Cs with a rating of 6, and the Electro Harmonix tubes I repleced with them say "6V6GT" then "electro harmonix", then "Made in Russia", then "04 08" and handwritten in Magic Marker on the top of the tube is a "46". Total mismatch?

This could be many things. If you know the tubes are good via a proper tube tester then it looks like it is time for the amp to see a tech's bench. It could be too many things to guess here without having the amp on a bench. I took the amp back to the store, and their tech guy says he thinks the Groove Tubes I put in to replace the Electro Harmonix tubes it came with are the wrong bias, and that the amp needs to be biased. Now, when I replaced the tubes, there was no problem. The distortion developed a while after I changed them out, not immediately, which I would have thought would be the case if the bias was wrong. And, I was under the impression that a matched set of replacement tubes wouldn't require re-biasing. I asked what biasing the amp for the tubes would cost, and they told me $30, if the tubes didn't need replacing, more if they did, of course. Am I being hosed or not?

Myles, I am having a problem with my Reverend Goblin amp. It's started distorting at any volume level. I have checked the tubes and they are all intact and firmly in their sockets. It has not been abused in any way, and it does it hooked up to any speaker, so it's not that. I don't know what the problem could be. Any ideas?

No matter what you use the amp is far into breakup at that point. That is what it is designed to do and no tube change will change the design. Do you know of a tube amp about that output & price that doesn't break up that soon, and isn't a total piece of crap? All these new amps of this type are designed to break up quickly, even the expensive ones. The cleanest of the small amps is the tweed champ. www.pierson-amps.com and other folks too Yeah, but they want a grand for that thing. DO you know of something for about the smae price point as the Valve Jr.?

No matter what you use the amp is far into breakup at that point. That is what it is designed to do and no tube change will change the design. Do you know of a tube amp about that output & price that doesn't break up that soon, and isn't a total piece of crap?

Myles, On an Epiphone Valve junior head, what tubes would you use if you didn't want the amp to break up too easily, maybe not till you got the volume knob past 12 o'clock?

The tubes say "GT6V6C", and handwritten on them is the number 6, and the letters IDC. I am still very happy with the way they sound. But, I remembered something a friend of mine told me once. He said that it would be easy to convert an amp set up to use 6V6s for 6L6s. Was he right, and what would be the resulting change in performance?

Well, it was a duet and I got the number off the box, so maybe "D" wasn't intended as an identifying nomenclature? What is the Gold Series? Another means to the end of getting more gold?

Myles, I got the 5751 for my Goblin, and didn't notice much difference in the reponse. Then I noticed one of the 6V6s had a hole in it's glass. I have no idea how that happened, the amp hasn't been anywhere but the store and my apartment. But anyway, I replaced the 6V6s with a set of Groove Tube Gold Series 6V6Ds, with a rating of 6, and I left the 5751 in the V1 slot. Man, what a difference! The Electro Harmonix 6V6GTs it came with sounded raggged and nasty in comparison. The amp no longer breaks up too soon, even in the 5 watt mode. But the clean sounds are complex and interesting instead of sterile and grainy. Overall, the amp seems noticeably louder and cleaner, but still has more than enough gain to break up easily if I want it to. I am very pleased. I noticed on the Groove Tube packaging it says that GT tubes rated 8-10 break up even later than the 4-6s, and I wondered what you thought of using those tubes for an amp like the Goblin. It seems like a low wattage amp like that needs a tube that will give it some clean headroom to keep from breaking up too much when you push it. What do ya think?

Regarding the Goblin amp, can you tell me which socket to put the lower gain tube in?

Myles, I just got a Reverend Goblin, and it's very agressive and neat, but I am having a bit of a time getting a clean sound I like out of it. I am wondering if a 12AT7 or 12AY7 somewhere in the preamp will tame it down a bit without neutering it completely. If so, where can I get such a tube?

Hey Myles, I have a Mark III Boogie, circa mid to late 80's. It runs just fine, but I was wondering when I ought to consider getting the caps replaced. How long before they get dried out enough to start causing me problems?

Geez, guys, be sure to let us know how the Classic 30 crackle problem works out and what was the culprit cause.