Another Amp Road Trip

[darwinohm]

Earlier this week I had posted about my Fender Twin Reverb Custom 15 repair. I am a sucker for new technology and good deals. Before that , many of you had given me some advice on tube brands and tubes in general. Again, Bassman speaketh with great wisdom. Earlier this week I had noticed a Bogner Alchemist 2-12 marked way down at the GC. I did a bunch of research and decided that this amp was a real decent amp according to owners. It is heavy ,at 90 lbs, but no problem for a kid like me. So, last night I stop in and strike another 10% of the clearance price and loaded it in the car, completely unheard or tested. As many of you know, if it doesn't work or you don't like it you bring it back. I have never done this but it happens frequently during the first 30 days. Get it in the garage and plug it in with great anticipation. Hit a few chords and sh-t, this is the worst amp I have ever heard. Little bass and what was there was muddy. It sounded tinny like a cheap solid state amp. Hook up the A/B switch and crank up the custom 15 and make a comparison. It was worse than I had thought. This 2-12 had a Celestion Greenback and a Celestion Vintage in it and should sound great. I hooked the twin reverb amp the 2-12 Celestions and wow! I then hooked the Bogner to the Fender 15 and back to crap. I went in the house and told Ginny that this thing is going back tomorrow. I did some research again and discovered a post from a guy who had the same complaint with his amp. This amp has 5 12AX7s and 2 6L6s and this guy put 12AT7s in the two preamp sockets. He said it almost blew him away when he tried it. It was a different amp. The 12AT7 has less gain. So this morning I am on a mission of repair. I stopped by The Good Guys in ST Paul and picked up some tubes. They are a well know amp repair shop. I told the guy what it was doing and what I was going to do. He smiled and said that he may approach it a little differently. I smiled and paid him. I needed some spare tubes anyway so this is a no risk operation. So, tonight I installed a set of JJ 12AT7s in the first two preamp positions and fired it up. Wow! does this thing cook. Ginny immediately closed the door going into the house. Another A/B with the Twin Reverb and a Legacy. Now were talkin'. You would not believe that this is the same amp. I think I lucked out again but this did make perfect sense to me. Bassman commented earlier this week that he likes to buy old tube amps and put good tubes in them. I don't like to return anything I buy and the fix was next to nothing considering the cost of the amp. Life is good here in Minnesota.-- Darwin I will sleep tonight!!! Think I'll have a beer on that.

[sam]

Darwin,

Great news, I'll have a beer in yer honor on both the low price deal (cuz I'm so cheap) and the tube difference. Bassman is a true wealth of knowledge. I've read some reviews of the Alchemist and they were good, but as it is said....don't believe anything you hear, part of what you part and question what you see! Thanks for the tip. Glad you snagged a GC deal as I did this week.

[blargfromouterspace]

That's very interesting Darwin. I wouldn't ever have imagined that changing the tubes could have such a profound effect. I've experimented with replacing 12AX7s with 12AY7s and haven't noticed a huge difference. However, I used the same brand (EH) when I replaced them. I'll have to get a few of those JJ tubes for my amps, just to hear for myself!

[darwinohm]

Blarg, I did not try new 12AX7s in the preamp positions but the sound was thin with to much high frequency. The bass frequency was not getting through. The 12AT7 is a lower gain and you would not believe it is the same amp. I would not say it is because of the JJs. The repair place has been using them because of the experience they have had with them. This amp came with Harmonix which is also Russian made as is the JJ. I would have not believed this experience if I had not heard it. The amp was terrible. --Darwin

[sirmyghin]

Try not to put too much stock in newer tubes, most are made in the same place. The only differences are the tolerances the re-brands sell them at, which is important, but makes the differences much smaller than they were 20 years ago. The 'bigger' names just do a better job of testing them for likeness. I have heard good things about 'valve queen', she apparently actually burns them in a bit before matching them so it is much more accurate over time.

[Muleya]

Very intersting, Darwin. I have tried those amps before and always walked away disappointed, thinking if that's what a Bogner sounds like, I've got no interest. My impressions very similar to yours...I've pretty much written them off!

Interesting that the lower gain tubes make that much difference! I believe in a previous post you mentioned that you only play your amps clean, so lowering the gain was a great idea...just gives you more headroom! I'm glad it worked out for you!!