Z Wreckish Combo First Time Build

[Soupdogg]

Hi Guys, I, like so many, have been blown away by the sound clips of these Dr Z Z Wreck Amps but as I'm from the UK they are completely out of my budget when you add on import tax on an already expensive amp.

I've never built an amp before but I really want to try building a zwreck style combo. I do have a lot of electronic experience but I have no idea what effect subtle differences in components make.

So for this reason I was wondering would anyone have an accurate schematic for a zwreck? Also, the PT with the multi-tap secondary for the Speed/Comfort setting is proving hard to find in the UK (240vac). Can anyone help?

[xtian]

Welcome!

Not sure there's a schematic in this thread, but does include posts from Dr. Z hisself:

ampgarage.com/forum/viewtopic.php?p=189625

[norburybrook]

Contact Mike at

http://modulusamplification.com/


He's a member of this forum.

He has everything you'd need. The transformers used are AC 30 transformers which are very big and heavy so I'm not sure how that would impact on making a combo, we both made heads.

Regarding the voltage tap, you could either get InMadOut transformers to custom make you what you want. They're based in Italy and make great transformers.

Or, you could fit a VVR which will achieve the same thing but with more flexibility.

Amp Maker in Cambridge sells a little VVR board/kit for £18 for Cathode based amps which would work fine I think. I was thinking of adding it to mine


Look for my Rocket/Z wreck build thread and you'll see everything you need there.



MC

[RJ Guitars]

Hi Guys, I, like so many, have been blown away by the sound clips of these Dr Z Z Wreck Amps but as I'm from the UK they are completely out of my budget when you add on import tax on an already expensive amp. ...

Slightly outside my budget here in the US as well but really nice amps. You won't need quite as much heater current available as you would for a true AC-30 so if you go with a custom wound transformer you might be able to use something a touch smaller (lighter) which would really be welcome in a combo build.

[Soupdogg]

I've managed to source most of the parts I need no from a UK distributor so all set to give a rocket amp a go.

A couple of things I'm wondering about having never built an amp before.

Firstly the quality of the transformers? Is this something that can really impact the sound of an amp? And if so, how.. noise, hum, tone/colouring?

The second thing is that I can get a lot of information on building a rocket amp which seems to be very similar to a zwreck, but from the clips I've heard there are definite tonal differences.

That zwreck tone seems to be compressed and there's a distinct contour on the mid tones that I can't put my finger on. I think the key must lie in the cap and resistor values?

I wonder if anyone has experimented with different values to attempt to tune a circuit to match a certain speaker/cabinet combination?

[norburybrook]

I think as long as the transformers are of a certain standard then there's not a great deal of sonic difference overall YMMV.

The rocket is a vey simple amp so I would say if you already have electronics knowledge then it shouldn't be to hard.

Regarding the difference between the Z wreck and rocket; it really is just a few different values of resistors and capacitors in one or two places.I think the tonal differences you might be hearing are to do with the speakers.
The Z wreck clips I heard the amp was paired with two alnico speakers which have a distinctive sound, I'm sure the rocket clips you hear won't be through the same blue and gold alnico cab.

Build your amp and experiment with speakers, that will make more of a difference than transformer makes IMHO.



Marcus

[RJ Guitars]

The output transformer will make a difference in the same way it does for any other amp. The rumor is that KF used a Dynaco 470 HiFi OT - maybe modified beyond just removing the UL taps. The 7-Layer Dynaco style winding scheme is believed to be significant in how this tranny works in the Rocket amp - This is sort of a "highly believed" but "lowly quantified" piece of common knowledge in the inner circles.

The PT secondary voltage(s) also matter as well as how much current they can handle. An AC-30 PT will run your voltages up pretty high and might require you to bias things a bit different on the output section.

I'm not sure how much the layout differences between the Rocket and the Z-Wreck impact the tone. I built an amp with a Z-Wreck style layout ( http://diyguitaramps.prophpbb.com/topic18.html ) and Rocket spec parts and it sounds very different than my original Rocket. I used a very different transformer set in them though so no real way to say they are comparable anyway.

I do greatly prefer the Z style layout and the Tejas Twister amp in the link above has the best MV scheme I've come across.