Mini Wreck?

[sliberty]

I am thinking about building a MiniWreckExpress. It will be an amp made up of a Trainwreck preamp and a single ended EL84 power section. As it will be single ended, the preamp will encompass the first three stages of gain, and then couple simply through and series resistor resistor to ground to the EL84.

Have any of you done this before? How did it sound? Was the agressive rich tone still there?

What about other amps built with the TW preamp? Liverpool? Rocket? Do they retain the agressive drive and harmoniic richness? I guess I am wondering how much of the Wrech sound comes from the preamp, and how much comes from the dual EL34's. If it's largely preamp, then the Mini should sound great.

Thoughts?

[funkmeblue]

I built a 2 6v6 single ended wreck........6sl7 preamp......sounds great......very complex...cleans up beautifully.......sustain for days

[sliberty]

Sorry if this question is elementary, but a single ended amp with 2 power tubes is new to me. Can I see a schem?

[UR12]

Steve

I sent you a PM

[Richie]

A few people have built a 2xEL84 type wreck..and also a wreck channel and a 18 watt marshall channel can be built into the TMB 18 watter.
Which is more i guess like a 1/2 liverpool

But some different options of what tubes you might want to use for the output.

Richie

[gearhead]

Although this doesn't scratch the single ended itch, UR12 built his Liverpool based on the first one (Ginger?), which has a half power switch. Knocks out two of the four el-84s.

It's not in the file section; as attached.

[whitewave]

and also a wreck channel and a 18 watt marshall channel can be built into the TMB 18 watter.

Richie

Really?!?
Can I mod one of the channels of the coming Ceriatone 18w TMB to go on the 'wreck tone?
Do you have any schematic of this mod?

Thanks.

[Richie]

Yes.. Geekmacdaddy also just built one and posted some sound files.
We offered some tweaked suggestions.. I think he has the info on it..
Mark huss might also have some info on his site..

http://homepage.mac.com/geekmacdaddy/FileSharing18.html

Richie

[whitewave]

I found Geekmacdaddy post and clips.
It seems a mod over a Ceriatone TMB 18w, isn't it?

I'm emailing with Nik decideng wich amp to buy.

18w TMB is an all around amp that I can't go wrong with, and OCD will help for going on leads.

Trainwreck is a beast difficult to tame, maybe a to noisy and powerful amp for my fingers.

Having them in the same chassis could be a great opportunity, but I've to admit I didn't like the clips. It has not the gain of famous geetrpicker's wreck videos, and not the same smoothness, it's harsh on middle-highs.

But Dumble sounds, Fuchs and so on, are what I would like to have. Jason Barker videoclips of Fuchs ODS are more than I can expect from an amp, I love them. Unfortunately I can't afford a Fuchs or a Two Rock, and I can't build one of them.

I was hoping wreckizing a 18w TMB could bring a very, very smooth lead over the normal channel.

Thanks.

[sliberty]

So, it seems that I might be the first to attempt the single ended Wreck, as all responses so far have been a little off topic (not complaining, just pulling us back on track for my thread).

I plan to gut my donor platform today. It started life as an AX84 P1, wqhich has a nice Heyboer 15 watt OT. I then replaced the power tranny for higher voltages, and modified the circuit values to be more like a Dr. Z mini Z (disconnecting the tone stack completely). Now my plan is build a TW preamp board, and install it to work along with the single ended power stage. This amp has always had an extra 9 pin socket due to a low power option I installed when building the P1, so I will have 2 12ax7's and the EL84 (perfect since there is no PI).

My PT puts out 260 volts. Since I am not powering EL34's, that should work out OK. I'll just have to play with the dropping resistors to get the appropriate preamp voltages once the thing is built.

If I can get even 75% of the agressiveness and complexity of my Express, I'll consider this a success. If it turns out a little weaker than I hope, I suppose I can always try to make use of the unused triode, but initially, I am going with the stock Express preamp.

I am almost finished with the 1st version of the schematic, and once its done, I'll post for comments.

[UR12]

Steve

Here is a clip of the amp I PMed you about. It is a 2 channel amp with one channel set up with an Express preamp feeding a dual EL34 SE output stage. Unfortunately the clip is using both channels combined but it should give you an idea of how the SE design sounds using EL34s. The clip was made using nothing but the amp and a LP (Neck PU), sm57 through a 1x12 Mesa cab.

http://homepage.mac.com/geekmacdaddy/.M ... 20neck.mp3

The absence of the PI gain may be a problem, but you could always use the extra triode to make up the gain missing from the absence of the PI.

Can't wait to see/hear your design, so keep us posted. Are you going self of fixed bias?

[sliberty]

Thanks Dana. Having never heard a single ended dual tube amp before, I am not sure how much of what I am hearing is due to that power section, but its not really the sound I am going for. I hope for something a bit smoother.

I plan to go self biased at first, and see how it goes. The design will certainly be simpler. Here is an incomplete (no power supply yet) preliminary diagram.

[UR12]

Looks good so far! You've really got my curisoty up on this one. Keep us posted as to how it goes. Sounds like it would be a really cool amp if ya can get that TW sound at 5-6 watts.

[sliberty]

I'll be starting by stripping the Mini Z today.

[sliberty]

Updated diagram to include general idea of power supply, but dropping resistor values are still to be determined. Voltages shown are approximate targets - I'd love your feedback on these.