Real TrainWreck mojo!

[jazbo8]

That's the reference TW video made by GK... the extra long guitar cable is used to attenuate the highs, info on the cab is somewhere on GK's site, I think...

[Chuck H]

GK's cab is loaded with the original green backs. Lots of miles and break in time on those.

Yes, Glen uses two 20' cables with his TW amps to double the capacitance at the input. This amount of capacitance probably won't make the amp "darker" but it will roll off that icy, glass chipping top end. With no grid stopper at the input and no bleeders throughout the amps probably exhibit that property in the worst way. Mostly when they're turned down below clipping.

The PI coupling caps on all the Express amps are .1uf, all the Liverpool amps use .022uf

Even though the difference between .022uf and .1uf for the PI coupling caps only affects frequencies below about 15Hz there may be a change in the feel of the amp since lower harmonics (that you'll never hear and the speakers can't reproduce anyway) may somehow affect tube character when clipping hard. But I'm just speculating on that.

P.S. I can't listen to any clips right now because I loaned out my computers sound system but I've heard all the clips anyway. This is another Express clip using a LP Junior with a P90. I like this one.

http://www.kometamps.com/sounds/demoalex9.mp3

[Chuck H]

On marshall type builds I do the improved grounding, and it makes a big difference on hum.
For example, no grounds on the rear of the Pots.
I see many things I would change on the grounding, and heater wire routing, but then again that may compromise the sound.
Also another thing that always bothers the hell out of me, is that unused gain stage.
I would have to hook that baby up!
T

That unused stage always bugged me too! I don't even know why but in my head it's just NOT ok!?! My similar circuit uses that stage for an effects loop. Which, as it turns out is not useful for every type of effect because the amp is usually clipping the power tubes hard. Oh well... At least I don't have a floating triode in the amps like those TW's or that one Bassman circuit that does that. Ick!

I also wondered about the "lazy loops" heater wiring (that's what they call it over at AG). After considering it I thought maybe it instigates enough inductance to null hum and keeps the actual leads shorter? I dunno. Most instruction on AC filaments include the term "tightly twisted" and that's how I've always done it. But all the Express and Liverpool amps have those lazy loops.

[big_teee]

Chuck, I like that clip also. It is more marshall sounding.
That amp is not near as dark sounding.
http://www.kometamps.com/sounds/demoalex9.mp3
It sounds a lot like my last 2204 with Short Bottle 6L6s, Fender Iron, and home tuned resistor and cap changes.
However the playing is much better!

[big_teee]

Here's an old Thread, that is a good read about the Komet 60 and Concorde.
http://music-electronics-forum.com/t1536/
The Clip that Chuck gave, is for the Komet 60, and supposedly does not have a CF circuit.
http://www.kometamps.com/sounds/demoalex9.mp3
The Concorde is a newer Komet design using the unused triode for a CF before the PI Circuit.
Here is the same song with that amp.
http://www.kometamps.com/concorde/mp3s/mississippi.mp3
These Komet amps cost nearly $4000 each so they should sound top of the line.
Compare the clips if you want to.
Where can we get the Schematics for these two amps, the Komet 60, and the Komet Concorde?
T

[Chuck H]

Ah ha! That clip is NOT a Komet amp, but a TW Express!!! They have in their sound clips because people wanted a side by side reference and they feel their amps stack up favorably next to it. And I DO think their amps sound great. Similar to the TW but, yet again, missing that extra spicy crunch on the attack and a lot less swirl and bloom. Clip #4 is the Komet 60 with the same player doing a slightly different version of Mississippi Queen.

Trivia: That player is Alex Garcia. And I also think he's a good choice for amp demo's He's got the touch for playing to the musical properties of any amp he's plugged into! I've had guys like that demo a couple of my amps on occasion. I'm always impressed by how much better they sound when it's not me playing!

The guitar player for the original Mountain version of that song is Leslie West. He also used a Junior (or maybe a Special) with a P90 for that song. It's reported that West's amp rig for that song was a stomp box through a SS PA head!?!

More trivia: West lost his lower right leg (in 2011?) due to diabetes. West is NOT Zakk Wylde's father. Many people think that because they seem close and Zakk calls Leslie "dad".

[big_teee]

I stand corrected!
I need to read all of it better.
They all sound like Marshalls to me.
I like the concorde as much as the others.
But then I am a Marshall, Farshall guy with the CF in tact!
We need some Komet Schematics.
I still bet the TW express used has a input grid stopper, probably 33k.
T

[ronh]

I built a TW express from a Traynor head. When I powered it up for the first time it screamed, not in a good way. Turned out to be lead dress. I didn't follow the
lead dress from Ceriatone. After I got the amp stable and played with it, I didn't hear any magic in it. One thing that I noticed was the B+ string is similiar to a Fender Princeton reverb AA1164. Maybe KF didn't invent the wheel, just tweeked until he got the results he envisoned. my 2 cents CAN.

[daz]

ok, i think i figured it out. It's the lack of tolex! Thats right...the wood is much more resonant when theres no tolex dampening the fragile harmonics.

[DrGonz78]

Don't understand the purpose of the 6 diodes on the Output tubes?

Referring to D1-D6 connecting plates to ground is very strange and have not seen that before. Was thinking about this today and just could not understand what is the purpose of these diodes. So I got researching and found that they were used on older Ampeg amps, hence the early years of KF. The link is an interesting thread to read and there is a picture linked on the first post as an example.

Diodes on the Power Tube Plates... [Archive] - The Gear Page

BTW Ken is mentioned in this thread halfway down...

[Jazz P Bass]

Yeah, the diodes are 'flyback' diodes.
They are 'supposed' to protect the circuit 'if' the OPT is not connected or if a transient tries to go above the power supply rail.
Personally, I do not like them.
A shorted diode circuit can kill the OPT.

[big_teee]

Good Research Doc.
I think KF, was concerned about Lead length and cost.
Don't think he wanted to fool with more fuses.
I answered another one of my questions about chokes, and the 25 Watt Resistor.
The Valve Wizard discusses the Choke versus the Wire Wound resistor.
It is way down the page under screen grid, and preamp supplies.
The Valve Wizard
Again KF seemed to opt for the cheap Resistor over the Choke.
T

[Chuck H]

Again KF seemed to opt for the cheap Resistor over the Choke.

I don't know that what he opted for was "cheap".?. It's possible he was opting for it's affect on performance. How many cheap amps exhibit some desirable tonal characteristic as an accidental result of their cheap-ness!?! He may have just been taking advantage of learned results.

That's the devils advocate in me. The more probable reality in my mind would be that he cobbled together an amp with spare parts and after some tuning it sounded really good. Someone asked him to build one for them and the design was launched. I actually think I read something to that affect once upon a time. Same with the Liverpool. Another customer, who was an avid AC30 user, wanted a similar amp that used the power section he was use to. So Ken built one. I think it's interesting that the first Liverpool amps had the same 6600 primary OT that the Express used. Implying that he was indeed cobbling with parts on hand. Some later Liverpool's used a different, lower impedance OT. Implying that he found a need to set up proper for both models. Still...

He was able to voice all those amps so that they delivered on the bloom and swirl. Giving them a vary vocal quality that the clones and copies lack. Incidentally, KF TW's are reported to sustain better than the clones too. I can't say about that because I've never played one.

Is it the general consensus of the posters on this thread that the extra "goodness" attributed to the KF built TW's is only hype? Because if so, this thread is going nowhere. My goal was to get opinions on why or how Ken was able to voice these amps properly when no one else seems to be able to. But if I'm alone then my thread has failed it's quest.

[big_teee]

IMO all builders are trying to find a cheaper way to build and sell their Wares.
Keep the quality up if you can with cheaper parts, I'm sure all of us do it too.
I've never been one for cork sniffing parts, if I can do something as good on the cheap!
I'm going to experiment with the Resistor vs. the choke, after reading the explanation by the Wiz.
I like his tone, but as far as the popularity of the amps, vs tweed, Blackface, and Marshall, It's just never seemed to catch on that much.
Seems to be more of the Mystique than anything else.
But, Heck lets chase the dream, I'm all for it!
T

[silverfox]

The essence of success regarding the Train Wrecks has to be similar to the Funny Car Industry. Everyone builds a motor that comes close to the winning speed. Only a couple of the builders consistently produce a "Best Design". Lots of little tricks they have discovered with an end result of a screaming build. Mojo?

Silverfox.