DLM Ideas

[Littlewyan]

I see the label on the back for the speakers reads 8/16ohm, so is one socket 8ohm and the other 16ohm or can you use either to mismatch?

[Mark]

https://tubeamparchive.com/viewtopic.ph ... lm&start=0
https://tubeamparchive.com/viewtopic.ph ... hlight=dlm

Above is a couple of links where people talk about the DLM.

https://tubeamparchive.com/download/file.php?id=1967

Allen's Class Act diagram above.

http://dnator.50webs.com/2strokewreck.html

In the link above this guy has read all the various posts on this amp and came up with his version. I think it is worthy of a mention. I've attached the circuit to my post.

I think his version of the harmonics control adds up as I've read where it only works with the master volume engaged. What I do find odd is the slope control, notice it isn't on the same plane as the other controls, it is almost like it is an after thought added to the amp. Also why is it to the right of the presence control and not near the tone controls which it affects.

I think the place to start with the amp is to look at the output tube. What rail voltage will you go with and what primary impedance.

Looking at the 6550 datasheet as this was the original valve the amp was made with, the options are;

(1) 250 volt rail with a primary impedance of 1.5K and an output of 12 watts at 7% distortion.

(2) 400 volt rail with a primary impedance of 3K and an output of 20 watts at 13% distortion.

A EL-34 has been substituted (rightly or wrongly) in the DLM, here are option with this tube.

(1) 265 volt rail with a primary impedance of 3K and an output of 8 watts at 10% distortion.

(2) 265 volt rail with a primary impedance of 2K and an output of 11 watts at 10% distortion.

This narrows down the primary impedance.

http://www.ax84.com/static/corepoweramp ... ematic.pdf

Above is the AX-84 20W SE power amp for reference.

I've included the picture of the DLM as it partially shows the circuit. The filter caps of the circuit are shown. To my eye there appear to be four nodes, two for the output tube and one for each pre-amp tube (this makes sense to me but it doesn't mean I'm correct.)

I'm wondering if the GZ-34 was used as it is supplying two 40uF filter caps in parallel?

SE designs do suffer from mains hum and a extra filtering can only help.

That is my thoughts and I hope it is of some assistance.

[Littlewyan]

His amp sounds amazing. I do hope to build myself a single ended nuked monster some time next year.

I come up with a design which 360V B+ but can't remember what primary impedance I settled on. Once you've got the output stage sorted though you can just tinker with different pre amps.

[Mark]

His amp sounds amazing. I do hope to build myself a single ended nuked monster some time next year.

Which amp do you mean?

[Littlewyan]

2 stroke wreck.

Also if the B+ was 360V then 4K Primary Impedance would be right for an EL34 I think. Well it will work at least.

[mhartman]

Since eBay ads disappear with time, here's the full ad (with pics):

“The Dirty Little Monster (DLM) is in clean condition, close to new was could be possible for a Trainwreck built in 1999.. It is the only Trainwreck that I received directly from Ken Fischer of Trainwreck Circuits. The amp is a prototype built on the standard Trainwreck chassis but doesn't have the traditional wood faceplate like the standard models. The DLM was built in 1999. The date of "birth" and name are stamped on the back top of the chassis. I have owned this amp for 14 years. And it has been very well taken care of. Anyone that has seen or owned real Trainwreck amplifiers know the wood cabinets pick up character (dings and minor scratches)after years of gigging. The DLM shows only the slightest of cosmetics minor imperfections . Also, as noted the only repair, the change of the power switch, was sanctioned by Ken Fischer.”

FS The Trainwreck "Dirty Little Monster" proto-type built by the late Ken Fischer. Single ended EL34 driven power section which puts out 12 watts. Built on the standard Trainwreck chassis, the tubes also consist of a Mullard GZ34 rectifier and a pair of ECC83/12AX7s. Comes with the Trainwreck manual (standard issue) with a personal note to myself. A copy of the original schematic for the DLM. And a signed letter of authenticity, with a little Kenny type joke at the end Also included will be an assortment of vintage EL34s (Mullard xf2, Mullard metal base, GE 6CA7, Seimans, and Amperex D getters ) and vintage 12AX7/ECC83 (Amperex Bugle Boy, Mullard, euro Philips, Mazda, Yugo, and various Amperican variants . The original knobs will be included, which were Sovtek amp knobs, I think the brown F type knobs look cool with this amp because of the bare faceplate. Only repair was the power switch failed, Ken gave me the part number and told me to take it to a reputable tech and have him replace it....believe me when I say that I begged him to change it for me, but he said it would be ridiculous to send an the DLM 6 thousand miles from Hawaii to New Jersey and back just to repair a power switch. Tone? Ken described the DLM as being the best Plexi type Marshall tone but with the signature Trainwreck clarity and definition. Great clean to mean tones from you guitar volume. Everything except metal type tones.

[mhartman]

...and the last pic

[RJ Guitars]

There is enough of a look at that that I was able to get some dimensions and I've added a DLM chassis to my other Wreck style offerings... hit the link below if that's of interest. I will maybe even avoid the dreaded IEC socket for this particular effort. I'll share the dimensions and a drawing with you as soon as I have them transferred from the rough CAD files into a jpg. It's probably safe to assume that this has another of my favorite Wreck items - the infamous "Stack o' Caps". Does anyone know differently? I can see the mounting screws for the circuit board and it looks like it is the TW standard. I don't suppose it will be hard to recreate the front faceplate. BTW, I'm good for a few bucks if there are a few hundered other builders that want to partner up and buy this thing.

[Mark]

LW, yes it is a nice sounding clip and he'd have to be happy with that.

RJ it is a nice thought to purchase this amp, but you need a means of approaching as many members as possible for donations. I'd be in for some cash <$100 to assist the members here, but I think we'd have a better change of purchasing the schematic rather than buying the amp.

I'm surprised the owner didn't put up a link of the amp on You Tube, $40K for something you've never heard is a lot of cash. Also given there are no clones of this amp and very few people have heard it in action, I dare say it will be like KF modified Fender and Marshall amps where they don't go for nearly the same money as the Express, Liverpool and Rocket amps. While HAD and Kenny's family might hate clones, they have created continued interest in their product which has led to the current high prices these amps go for.

*EDIT: This is what I got from a You Tube search on Trainwreck DLM.

https://www.youtube.com/watch?v=0e-jRpFik3c

Perhaps this is something we could pitch to the owner, that should it not sell, then allow us to clone the amp which in turn will create greater interest in his amp?

Getting back to the circuit, I was thinking perhaps the slope control is a pot in series with negative feedback loop. A small cap across the pot would give it a midrange control like effect and account for it's position near the presence control?

Has anyone built an amp with the 220X pre-amp and a single ended output?

This has probably been done at AX-84 site and there may be remarks about the amp there.

http://www.drtube.com/schematics/marshall/jcm800pr.gif

[Littlewyan]

Its quite possible the slope control is set up in such a way. I cannot believe that its a simple midrange control in the tonestack, the wiring will have to go past the master and presence control it will surely cause issues with feedback.

The only thing that would make the amp in that link better is NFB as the bass isn't very tight.

[Mark]

Do you have a link for the real DLM amp?

I've never heard the real DLM. The core size of the output transformer will dictate the bass response, my Champ clone sounded much fatter with a Mercury fat stack output transformer.

[Littlewyan]

No I've never found a clip of the real DLM. I see that the listing on ebay has now ended, don't know if it got sold or not.

This is off topic but whilst I was googling Trainwreck DLM I came across this: https://reverb.com/item/122018-trainwre ... le-bubinga

How cool is that! Its pretty pants the company that made it has copied Komet's style of head and the guy has listed it as Trainwreck style but it looks great.

You thinking about building a DLM Mark?

[Mark]

The message on eBay is seller has accepted the best offer. I'm sure if that means it was sold or that is a standard reply that comes up when the auction ends.

The amp was also listed here.

https://reverb.com/item/392139-trainwre ... nster-1999

As far as cloning one, 12 watts is still a loud bedroom amp. I'm still liking the idea of the 4-4-0 Express.

[statorvane]

Has anyone built an amp with the 220X pre-amp and a single ended output?

I think the High Octane is such an amplifier (AX84). There's also some action along those lines over at SEWATT.com - 6V6 power tube. I believe this is a PCB that is designed to fit into an Electar Tube 10, or Epiphone Valve Jr. 5 watt amplifier.

[angelodp]

This does have that hi gain thing going.

[IMG833]http://i260.photobucket.com/albums/ii9/angelodp1/565-redo-pin-swap-boostMV-2-Wloop-Voldiv4_zpsf90ca48b.jpg[/img]