Glen Kuykendall T Drive Transcripts |

Glen K Transcripts


Wed, Jul 23, 2014 at 6:24 PM


Hello from Nashville! Glen Kuykendall here, the guy about the “Trainwreck” type pedal. Folks know me on the web mainly from my Youtube videos featuring original Trainwreck amps, ‘59 Les Paul, etc...

Anyway I’d be quite interested in putting in my input on a pedal’s development. I wouldn’t be surprised if “my take” and “input” on it would help it’s credibility considerably as many folks these days (and folks on the ampgarage forum, THE forum for builders of these) tend to use my videos and instrumental CD as the benchmark of what to expect with these amps.

That said, I’m no star in the music world though I am a full time working musician in Nashville who also puts more than the usual amount of effort into getting the best tone possible no matter what gear I’m using.


Glen Kuykendall

Fri, Jul 25, 2014 at 12:33 PM

Hey Glen! 

?Indeed! I've admired your videos for years! What a pleasure to correspond with you here!

Which model TW do you have?

I wish we had connected last week when I was in Nashville for NAMM. Bummer!

Let's start talking about things that you think should be a part of this.

Best regards,


Mon, Jul 28, 2014 at 12:14 PM 

Dear Mason,

I have an ‘89 Express (owned since new direct from Ken) and an ‘85 Express. There are two main periods of EL34 Express amps (and EL84 Liverpools), the first have off the shelf Stancor output transformers and the later have Pacific transformers.

The Stancor amps tend to be sweeter, more bluesy sounding and perhaps more versatile. The later Pacific amps are more aggressive and more midrange forward. Basically I have one Express from each era.

I owned a ‘90 Liverpool for about 8 years but I no longer have it. I’ve played a couple original Rockets but have never owned one.

IMHO, a huge part of the Trainwreck sound (speaking mainly Express/Liverpools) is the response and feel from clean to mean all with the guitar knobs. Though they have quite a bit more gain on tap than most any typical single channel amp, they clean up very well by backing the guitar down. Also the amp has quite a bit of compression but it’s not the loose kind of compression of a tweed Fender or JTM45. It’s more like a nice studio compressor placed after the microphone. The benefit of this is mainly in the volume leveling effects, and the amp doesn’t actually sound squished. With the amp set at fairly decent gain levels IF you back your guitar down to say 3 you will get excellent cleans but the volume will be almost the same as fully cranking your guitar into full overdrive. To me this makes working the guitar knobs quite usable on stage in a band situation, and quite expressive pardon the pun. It’s almost like taking an overdrive pedal and putting a compressor after the overdrive. Another good comparison is an Express (or Liverpool) can actually respond a bit like a germanium Fuzz Face, however the actual tone is MUCH more traditional and usable for a wide range of playing styles.

The Liverpool amps have a very similar response and gain to an Express, the difference being EL84 output stage. These amps are a little bit more extended in the top end like an AC30, and have similar clean to mean response as an Express, but with perhaps a tad bit more volume change between the two which is a little bit of a let down compared to an Express. In other words they don’t quite have as much of a volume leveling effect. Gain between the two amps is almost the same, but the EL84s seem to allow the Liverpool to get away with it’s extra brightness ala like a nice AC30 can. My bet is the natural volume leveling effects in the Express is quite dependent on power supply sag used on purpose, and Ken’s use of a big simple power resistor (instead of a choke) on the B+ is perhaps part of his recipe for this. Many amps (especially older classic Marshalls, and Fenders) clean up well from the guitar, but I have never found any that can be set for as high a gain as an Express but still clean up on the lower side of the guitar knobs.

It should be mentioned the guitar pots have to have quite slow taper to work well with a Trainwreck, and in my experience you typically don’t need treble bleeds on the guitar pickups at all.

The gain levels of Express/Liverpools is actually quite high for a single channel amp, and when on 1/2 they tend to be as gainy as a fully dimed (all knobs) 4 input Marshall. A fully dimed Express is “metal” levels of gain.

Typically (speaking of Trainwreck amp clones here) IMHO the most often missed aspect from custom builders is not getting the amp to clean up as well (and with the volume leveling compression) of an original Ken built amp. Also on the originals there seems to be a sweetness in the extreme top end which helps the amp not sound shrill or too bright. Almost like there is a little bit of extra high end compression and smoothness, that only kicks in on the high note range. Plenty (perhaps most) clones tend to be harsher than an original Trainwreck, and it’s this extra harshness that baffles many builders.

To me if you can build a pedal that folks will like to simply keep clicked ON and control it from the guitar (for clean to mean) you will have an excellent start right there!


Glen Kuykendall

Mon, Jul 28, 2014 at 1:55 PM


?I think you'll find this is what this pedal does very well, almost cleans up like a really amazing Fuzz, but is more overdriven in tone, with quite a bit of gain.

?I noticed that too on the ones that I had here and still have here.

You'll have to let me know how they stack up to your ear.

?I don't do treble bleeds either, good to note.?

?How soon would you be open to checking out a prototype?

Best regards,


Tue, Jul 29, 2014 at 7:33 PM


My schedule lightens up quite up a bit after August 18th, so any time after then works well...

It would be cool to play the pedal on a few gigs in addition to studio testing up against my Express amps.

Do you have a particular amp or amps that you are doing most of your testing with these pedals?

My main “pedal board friendly” amps are these five:

‘68 Marshall Plexi Super Bass 100 w/4x12
‘59 Fender tweed Pro (with 12” on adapter baffle) ‘64 Fender blackface Deluxe
Early 70s silverface Fender Deluxe Reverb
‘83 Fender Champ II


Glen Kuykendall

Wed, Jul 30, 2014 at 12:38 AM

Hey Glen!

We should definitely schedule for that time then to get a prototype to you!

I've been using really typical backline amps to test it agains the Express amps I have here. Things like Fender Hot Rod DeVille's and Deluxe's.

Probably the Blackface Fendery stuff would be good, but I'll let you be the judge.

Mon, Aug 25, 2014 at 5:54 PM

Hey Glen!

I hope you're having a great start to the week!

Have you had a chance to plug into the pedal yet. What do you think?

Best regards,


Mon, Aug 25, 2014 at 7:57 PM


I did (the day after I got it) but I wasn’t sure the best way to describe what I think it needs to both sound and feel like the amp it is replicating.

That said, over the next couple days I’m going to set up my original Trainwreck setup, and ‘64 Fender Deluxe setup WITH the pedal side by side to compare.

During my first listen I was comparing the ‘64 Fender Deluxe/Vertex combo against the Trainwreck amp albeit with a power attenuator on the Express set really low.

That said at “bedroom levels” the attenuator colors things and makes the comparison somewhat flawed.

My plan is to mic up both rigs in my isolation room using identical mics and listen to both on my studio monitors at the same net volume.

I’ll keep you posted!


Thu, Aug 28, 2014 at 10:11 PM


Just finished doing a somewhat clinical comparison of the Vertex T*Preamp pedal vs my ‘85 Trainwreck Express, x3 clips and x6 pics attached.

I setup the T*P with a stock ‘64 Fender Deluxe (non-reverb model), vibrato channel volume 3, Bass & Treble both on 5. At that point the amp is remaining clean and not adding much coloration. It is a healthy amp with recent power supply caps and fresh tubes.

When the pedal is turned off it’s a typical clean blackface tone. Speaker is a Celestion G12M Creamback in the combo cab itself. I ran an 18’ Mogami cable before and after the pedal to the amp.

The original ‘85 Trainwreck Express (w/EL34s) was setup my typical way running it with x2 Mogami 18’ cables in series with a coupler, into my ‘68 Marshall 4x12 cabinet with similar era Celestion G12M Greenbacks.

The volume was almost on 3/4, which may seem high on an Express but the volume pot in this particular amp has such a slow taper that on 3/4 is more like my other Express (and most clones) on 1 or 2pm. Even on 3/4 the amp had a bit more to go.

Treble & Bass were both on about 1pm, mids & Presence both 12:00. The bright switch was full on. I didn’t record my other Express, an ‘89. It is perhaps even a little more mid focused than my ‘85, and has a little less clarity. That said, the extra mids in it make it real lively and sustain crazy when played near the cab in the same room. Both amps clean up as well and circuit inspections show that they are near identical, short of my ‘85 has the off the shelf transformers Ken started with where my ‘89 has the Pacific ones Ken had built for him in his later years.

I noted from my Neve preamp levels and DAW meters that the volume off each miced speaker was almost identical, being the Trainwreck was unattenuated (and loud) but going into a 4x12, and the Fender was set modestly but driving only 1x12. Point is, the Trainwreck was pushing it’s full rated power 35 watts divided into 4 speakers (about 8-9 watts per speaker) where as the Fender was kept below clipping and was probably pushing about the same wattage (8-9 watts) into it’s one speaker. Point is, speaker compression or slight cone breakup was probably about the same between the two rigs.

Guitar was my 2007 Fender Relic Strat with Lindy Fralin single coil pickups, and a Suhr hum cancelling back plate.

Both amps were miced with a Shure SM57 just off center of the speaker, using Neve 1073 mic pres and no EQ or compression was used. There was a tiny bit of Lexicon PCM60 reverb on both tracks so it doesn’t sound unnaturally dry.

I matched the input levels to within 1 db. Personally I like the fatter and smoother tone of a dynamic/ribbon two mic combination but keeping it simple here for comparison sake with just 57s.

To my ear the pedal still needs some work to be convincing.

That said, in regards to the T*Preamp here are my feeling of where the differences fall and improvement is needed for this to really impress folks. I’d personally love to have something in this department on my pedal board since my two original Express amps have mainly become studio amps and don’t see much road work due to their rarity and current value.

The Trainwreck is more mid focused, plus it has a bit more of that Marshall grind to it making it sound more forward and alive in the mids and lower trebles. The T*Preamp sounds almost too wide EQ bandwidth wise, and is almost scooped in the mids at the same time.

The Trainwreck is quite a bit tighter in the low end and much better for power chord work, the T*Preamp almost sounds a bit like a Fuzz Face in that it has a fatness that gets in the way and makes it loose sounding on lower notes. Mid range notes also sound a bit spitty, also like a Fuzz Face.

The Trainwreck has louder more audible cleans when the guitar is backed down the same amount. You can even see it in the wave form pic (attached) that there is simply more usable level going on. The pedals cleans up well enough, but once I hit a few low notes it gets a bit farted out.

It’s almost like the Trainwreck clips across the audio band at the same point, as opposed to the pedal seems to clip first in the lows...enough to make it sound and feel quite a bit looser.

The Trainwreck sounds more like a live amp, the T*Preamp sounds less convincing and more pedal like. For example the Zep stuff sounds a bit more like a live rig, where the pedal sounds more like a simulation.

The T*Preamp probably could have it’s low end rolled off a tad which might help the tightness, but the mids would still need to somehow be more lively. I also noted when I pushed the pedal with lower notes (especially on the neck pickup) it lacked clarity and the guitar’s tone was masked.

You could simply hear the guitar’s tonality better on the Express.

The T*Preamp almost needs to have more compression to level it’s volumes when working the guitar volme (clean to mean) BUT it already sounds too compressed in the lows. The trick will be too add volume leveling compression, but make it sound less compressed at the same time.

To me the Express almost sounds like an amp with a studio limiter inserted post amplifier, as it has a squishy feel to it but doesn’t ever sound too mushed out IMHO. Part of the feel however is something that you can’t quite demo in a clip, but I could feel in person quite noticeably. Point is compression feels nice when you play and makes your dynamics seem to bloom and jump out in a good way, the pedal lacks this bounce to it.

The pedal doesn’t sound or feel like a Trainwreck Express yet, though it has a good start especially that it retains clarity when you back down for cleans. Most dirt pedals fall very short in this department, though I guess many pedals are simply built for the keep the guitar full up crowd. Anyway this is my take on it at this point and hopefully I’m not too brutal!

Glen Kuykendall

Fri, Aug 29, 2014 at 6:18 PM



Wow! You really did a great job! So thorough! Thank you SO much for this.

This will be incredibly helpful to me to implement's really a game changer. How soon would you be ready to receive a updated version?

Do you want me to send you a label to send that one back?

Best regards,


Fri, Aug 29, 2014 at 11:37 PM


I’m glad I didn’t blow up your computer too badly!  That said, I’m going out of town tomorrow until next Tuesday but after that I can deal with getting the pedal to the post office and/or hearing another pedal when you get it going. Sure go ahead and send a label, though I won’t be here to ship until Tues or Wed of next week. Finally a little time off over the next 3 days.

Thanks, and looking forward to see what the tweaks on the pedal circuit will bring. I also noticed the pedal had a very hot output and unity gain was way down on the volume knob. That said, that is probably a real easy fix but just thought I mention it.



Sat, Aug 30, 2014 at 2:10 PM


No blowing up was really the best information I've ever received from someone helping me with a pedal. I was absolutely astonished! Thank you!

No problem. I'll send you a tag to ship it back. I've cc'd my colleague Greg so that he can send one to you ASAP and you can print out at you leisure.

Best regards,