AMP Repair and What brands do you usefor tubes.

Had a gig last weekend and my 65 twin custom 15 worked fine. When I shut it down at the end of the evening it had a slight burning smell. Never a good sign. I plugged it in last night to test a Strat I had just repaired for someone and it was dead. Removed the power head from the cabinet and found no heater voltage to the tubes. Discovered the 10 amp heater fuse blown and the fuse holder burned on one end with damage to the circuit board. I suspected what the problem was but pulled all the tubes and measured the resistance of all the heaters and resistance to all grids. No problems. As I suspected, the problem was the fuse holder end possibly not being tight enough and lost temper as it heated more and more. I bypassed the circuit board and installed a heavy duty auto type fuse holder directly from the transformer to the heater circuit. Plugged it in on the bench only testing the heaters. Everything was cool. Hooked up everything else, turned on the standby and does it ever work nice. I had it on for a half hour and checked all connections I had made for heat. It was fine so I reassembled, tested and had a permanent fix for less than $6 including several extra fuses. A shop would not have done this but replaced the pc assembly. I like pc boards and think they are more reliable than point to point but anything that stands on the board such as fuse holders are subject to failure. I bought this new at the GC as a demo but I am sure that someone had returned it. I bought it as is and It has been intermittent a couple of times. I suspected a tube but this is it. Point to point wiring is only as good as the person who soldered it. I just saved a bunch of money to put toward the next guitar. Boy, did I talk this one up to Ginny. Her first question was "why do you use a tube amp if it so expensive to fix"? That shot me right out of the saddle.

I am going to retube this at some point. I do not use distortion and it is a quiet amp and extremely clean, and that is what I want. So what do you guys think on tube brands? The output tubes are Russian and I would bet there is not an American tube in it. I need the scoop before I buy. Thanks ---Darwin

That's a nice cheap repair. Knowledge is such a great thing to have. Surely your wife is winding you up, calling $6 expensive!!!

Blarg, I told her I had saved myself $200 which is true. Thats what I was trying to impress her with. She then made a good point.!!!

I can highly recommend JJ Tesla tubes from Bob at Eurotubes.com. Bob can mix and match them to give you early, mid or late breakup. His communication and customer service is second to none. The tubes took only 4 days to reach me in Australia.

My Blues Jnr was always on the shrill side using the standard Groove Tubes and Tung Sols, but the JJ Tesla's mellowed it right out and now it delivers a beautiful, rounded clean sound.

I can highly recommend JJ Tesla tubes from Bob at Eurotubes.com. Bob can mix and match them to give you early, mid or late breakup. His communication and customer service is second to none. The tubes took only 4 days to reach me in Australia.

My Blues Jnr was always on the shrill side using the standard Groove Tubes and Tung Sols, but the JJ Tesla's mellowed it right out and now it delivers a beautiful, rounded clean sound.

Hey, thanks Philby. I have a Fender Blues Junior too. I might try your advice and swap out the standard tubes for those JJ Tesla tubes. Good post. Thanks.

BTW. Anyone here had any experience of installing any of the BillM mods for the Fender Blues Junior? It would be interesting to hear some feedback, both positive and negative. Are they something I could undertake myself or should I go see a good amp tech? Thanks.

Bill

That's great that you fixed it yourself, Darwin. I have a little tube amp knowledge, but probably just enough to be dangerous! Though I belong to a couple of forums for DIY amp folks, and while I'm not terribly active there, I've always been able to get help in regards to an single-ended amp someone built for me a few years ago that I've modded a couple of times...the last time fairly extensively.

Don't have a lot of recommendations on tubes, as I'm still figuring the different brands and types out myself. I've tried several different 12ax7s...JJ, Tung Sol, Electro Harmonix, and the Sovteks and Shugangs that came stock in the different amps I've had. I've found the EH to be quite good, and quite affordable. The Tung Sols seemed to have a little more gain, so maybe not the best choice if you play fairly clean.

Darwin,
NOS or even used US/UK made tubes are well worth it if you want the best tone possible from your amp.
When you hear what a set of RCA 6L6GC tubes as well as an upgrade in the V!,V2 position in your preamp tubes (12AX7 or 12AT7), you will be floored.

I often find US tubes in older off brand amps and buy the amps just for the tubes.

I would rec just the 12ax7 tubes be replaced with the NOS tubes if the cost is too high. I know this is not cheap to do these days.

bassman

Great repair. Tube amps can be a hassle can't they? I sure think they are worth it for guitar, but i suppose some folks have great solid state sound. I just don't know any.

I had better get the disclaimers out of the way, first, I am the opposite of you. I almost never play completely clean, not because I don't want to, but I mostly play a deluxe reverb, and why it has a volume knob is beyond me. It is absolutely a one trick horse, and basically has an on/off switch--by that i mean it sounds great from 3-7 on the knob. The difference in volume is not all that great.

Second, I have have never gigged my twin reverb. I love the clean tone, but to get it to break up makes peoples ears bleed.

So, you can tell I am an expert. Lol. But I have had great success with both jj and electro-harmonix current issue power tubes. To my ear NOS power tubes just aren't worth it, and it is kind of a mute point because I can't spend $150 bucks on a set of 6V6's that I carry around and gig with, and go out pretty regularly. A couple of the other posters noted, that there is a lot of difference between tubes, and good vendors can test and send you what you want.

Pre-amp and effect tubes are a different story, again for my ear. Sovtec and and tung-sol make some tubes that I am happy with. But NOS/US/UK Tubes are better, and make a more noticeably difference here than power amp. I am using a lot of mullerds right now, but also have Raytheons and RCAs in the past. All good.

Well, that's more than I know. Cheers.

I like the Winged C/SED 6L6 tubes in my Mesas. I also have a set of the Groove Tubes 6L6-GEs and they're good too. The Winged Cs sound like an NOS tube--they are strong, solid, non-microphonic, and durable--just what you want in a high-powered combo.

I usually have a mix of preamp tubes in my amps: from JJ, Mesa, EH and Groove Tubes. I like the GT12AX7-M Mullard clone in the V1 socket of the Mesas, but they're hard to find, and I think discontinued. One company's tube might not sound good to you in V1 but works great in another socket. Experiment!

Good luck!

Bill

I also prefer JJ's from eurotubes...
Let say the NOS tubes are great, amazing, magical etc.... That's fine while you can get and afford them, then what?
I'd rather get tubes from either Eurotubes or Doug's tubes, they check every one and you can get the specs and reorder the exact same sound for your amp if you like it...

I'm not trying to put anyone down that likes NOS tubes, I have some in an amp or two and they are great but I wouldn't search for that tone again, I'd get some from a couple suppliers that test every tube and then keep the ones I like the best and sell the rest...

Nice repair, Darwin! I prefer NOS tubes. Before I install NOS tubes in an amp I use new tubes to make sure everything is OK with the amp so that it won't eat up my good tubes. I've had good luck finding tubes at auctions.



I paid $50.00 a few months ago at an auction for an old tube caddy and got the tubes you see on the front row plus another 100 tubes I'll sell on Ebay!

I also found a box of diodes in the tube caddy and I used them to fix the ignition switch on my Arctic Cat. I saved by $75.00 by repairing the switch instead of buying a new one!



Sprinter 92