Please forgive me... A blasphemous question

[LeftyStrat]

Doh!, my bad, I'm still on my first cup of coffee. The 5v connects to 2 and 8.

[ampdoc1]

I've built two TW clones and substituted a 12AU7 for the first tube and a 12AT7 for the second, in both builds. I did this originally just to lower the hiss. It did that and also allowed me to get a great clean sound by turning the guitar volume to 2-3, while also retaining the "touch" and sensitivity for full out killer lead tone. You might try this before you get into heavy modification.
They were still really loud, so I made some other mods to get better bedroom levels. Let me know if you are interested in anything like that.

D Hicks

[ricks57custom]

Ampdoc,
I've got a ppiv master in it that works pretty well. It adds a touch of saturation at lower volumes and will oscillate slightly if both the master and volume are turned up to 10. I am always interested in mods or tweaks to get better sound at lower volumes. Please feel free to send me any tweaks you suggest.

Thakns,
Rick

[Flames1950]

Hey Rick,
I've been busy moving to a new house and then got sidetracked building a Metro JTM45 so I missed this seeing thread earlier, but your comments about the gain really hit home with me.
I got back to tweaking this amp and correcting some mistakes a week or so ago. Once my wiring was cleaned up and my mistakes corrected (the ol' switcharoo the OT primary wires around....) I was a little stunned at the obscene amount of gain this thing had. I just didn't think I'd have a use for it built with the version A1a preamp as drawn.
I would have tried 12AY7's across the board to cut it down, but I didn't have any. My solution started by removing the cathode bypass caps on the first two stages. Oh, so close.....but still too much fizz and distortion.
So at the suggestion of another MetroAmp forum member I tried lowering the resistor to ground going into the third gain stage, in my case from a 150K to a 68K loaded the signal down just right. Now I've got plenty of overdrive for a player used to Marshalls -- 6 or 7 is great for most rock chores with a Les Paul -- I can still clean up pretty good with my volume control, and I can still get what for me is too much gain and overdrive by diming the amp. It's also a wonderful blues and rock amp with a Strat on about 7 as well.
If you haven't torn into yours too bad yet, some of these ideas are real easy to try, and you can just swap the original components in if you don't like the results.

[Elcabong]

You guys got me wondering. Is it still worth building one? I have bought an OT specifically for this project but now, my motivation is on the down side.

[glasman]

You guys got me wondering. Is it still worth building one? I have bought an OT specifically for this project but now, my motivation is on the down side.

They are still pretty cool amps. I built the A1A version and it is a great amp. I would say it is NOT a jazz amp, but if you are looking for an aggresive rock and roll amp this is one way to go.


Just my 2 cents......

Gary

[Robert]

I think you should consider the Express clone, A1a, as a unique amplifier platform, that is not widely used due to scarcity not poor tonal quality, to derive a sound from that you enjoy. It is an amp capable of providing you with an aggressive distortion if you want it and good touch response. There are numerous, documented and easy ways to modify the distortion characteristics of the amp. I have found it very transparent in that a variety of guitars maintain there unique character, unlike some modern popular high distortion amps. I also think it will take some time to get the most out of both in terms of playing and modifying to taste. I have tweaked alot and will tweak alot more. Actually might never quit tweaking. I think the correct transformers are a must to get the most out of the amp. If you already have the OT, hopefully the correct Pacific or Heyboer, you will probably not spend that much more to finish the project. None of your parts will really be lost anyway. The only way to know is to build it.

[Elcabong]

Thanks guys. I feel better about it now. It is probably the fact that the forum is not as active as some others that made be feel alone with my project. There are not many sound files to listen to either.

Oh, by the way, I bought an Heyboer OT so I understand this is a good start.