A quick clip of my TWreck clone

[ricks57custom]

Sorry I haven't responded sooner. Yes, it's true my Trainwreck has ceased to be and is now becoming a JTM45-like amp. I needed to find out if this amp was for me and now I know.

To answer your questions I used Mallory caps with the exception of the PI where I had some .1 Sozos. It was schematic version A4 that I used. I used the 6400 taps from the OT on the build.

I don't want to discourage anyone from making this amp. It's a tastes thing that I wouldn't have any known had I not built it. I think this amp still sounds very good for high gain applications.

Hope this helps,
Rick

[Snapcase]

Thanks for the info, Ricks57.

I'm involved in another poject right now, but I want to attemp a Wreck as my next project and didn't know which version to build. There's too many versions out there for a single amp!

At least for me, A4 is the right way to go since I listened to your clip.

[HiGain]

Sorry I haven't responded sooner. Yes, it's true my Trainwreck has ceased to be and is now becoming a JTM45-like amp. I needed to find out if this amp was for me and now I know.

Hi, Could you say what about the JTM-45 you prefer, and ultimately what you didn't like about the express?

Thanks for your feedback,

Jake

[ricks57custom]

Higain,
The two things I noticed the most were:

1) The sound of it was fatiguing to my ears after a half-an-hour. I wanted to turn it off because my ears were ringing more then usual and I'd have a headache.

2) I'd play it and think it sounded good and then I'd A/B with my Marshall Plexi and be dissapointed. I think I'm just a Marshall guy.

The JTM45 will be pretty smooth, fat and warm. The Express has a lot of gain (which can be a good thing) but guess I like it less and less. I prefer to have a great solid palette to work off with my pedals (delay, flanger, overdrive, etc). I love just plugging in and going for it but I find I write with a more textural approach.

I'm in no way trying to dissuade anyone from making one. They sound better than most amps out there. Besides, who knows how close I was to real one. Proabaly not at all. However, it was a great learning experience to build one from scratch.

Thanks to all who helped,
Rick

[HiGain]

Thanks for your reply. I know what you mean about the ear fatigue. Some day I'll have to look in to a JTM45.

Jake

[ricks57custom]

Just a quick report: I switched over my Trainwreck to JTM45-type specs and it just plain ROCKS! It's still got a nice amount of gain but not over the top. I LOVE KT66 tubes! They are very creamy. Even with a PPIV master, the thing just plain rocks. I don't want to derail all the people having luck with their TWs. I just know that this amp is exactly what I heard in my head.

Best of luck to everyone with their builds,
Rick

[Elcabong]

Hi Rick,

what is important is that you like your amp. How are the Heyboer transformers doing in a JTM45 configuration? Have you lowered rail voltages?

I have a JTM45 populated board waiting on my bench; it is something I plan to do after the Wreck. Unless I go for a SLO.

[ricks57custom]

Elcabong,
The Heyboers are doing well. It didn't take much to get it in bias and they have an aggressive edge that makes it sound mean and growling. I'd be willing to bet that it has a bit more gain than most JTM45s. If I have a chance I'll post a sound file. It is quickly becoming one of my favite amps.

[Moose]

Those trannies are good for KT66s as long as you keep the wattage below 45W or so. Run them at 425V or less and/or cathode biased and the OT will be well within specs. It's easier to get the KT66s biased and sounding good on the 6600 tap, too.

Someone here built a harp amp with a set of trannies running close to 450V, an it worked out, though I wouldn't suggest everyone try that.

And I, too, LOVE the KT66. I was running my wreck with them before I switched over to 6v6 and I really dig the breakup and how it comes on without the same sizzle as an EL34.

I prefer the wreck style touch sensetivity to a JTM45, but I undertand the longing for that sound. Once you get the Beano tone stuck in your head, that's the circuit to replicate it.[/code]

[Elcabong]

Run them at 425V or less and/or cathode biased and the OT will be well within specs.

Pardon my ignorance, Moose, but if the bias voltage is readjusted for the 6V6, is'nt it the same as having them cathode biased?

[Moose]

Pardon my ignorance, Moose, but if the bias voltage is readjusted for the 6V6, is'nt it the same as having them cathode biased?

Certainly not.

The express is a fixed bias amp -- which means that a fixed voltage is applied to the grids of the power tubes to bias the amp.

Cathode bias is when you put a resistor on the cathode of the power tubes to bias them. Totally different technique.

Fixed bias can usually produce a little more wattage than cathode biased, and tends to provide a snappier response. Cathode is a little softer because the amount of voltage drop goes up as current goes up, so it is a touch easier on tubes.

In the case of a 6v6, you can just jam them in there, twiddle the bias trimpot until you're dissipating about what you think is correct, and start playing. They take an adjustment, but still use the same fixed bias scheme the EL34s (or 6l6, or KT66 if you like) use in this amp.

[racerx23]

hey rick

that sounds fantastic, have you documented the changes?
and which kt66's are you using with which preamp tubes.

craig