Z Wreck

[rooster]

Hey, I can't stop staring at those red Fender style knobs! Have any of you seen those for sale anywhere? I find it hard to believe that Z is having those made exclusively.....

[Ken Moon]

I noticed none of Brad's amps have IEC power connectors. It looks like they just have the old-style strain relief, unless it's some other type of small round connector.

The other zwreck pics all show a typical IEC input.

Whazup with that?

[Ian444]

8uF filter capacitors for the preamp tubes, and a ceramic capacitor from the anode of the first stage, interesting.
It's a really neat build, nearly as good as some of the ones on this forum

[M Fowler]

Brad's Zwrecks aren't the production models they were built after the flood I believe to replace the original's destroyed.

The give away Zwreck was different as well.

Still waiting for my cabinets and need to start punching holes to get started on my second wreck.

Mark

[DustyBadlands]

[M Fowler]

Getting there huh!

Not sure how Dr Z did the dropping string. In the gut shot photo there is three wires between the boards orange, black and brown.

Brown to the 100K pair B3 from B4 cap 8uf
Orange to V2 pin 1 100k B4 from B3 cap 8uf
Black to 20k on board B5 from B2 cap 40uf

Well at least that is how I wired it.

[DustyBadlands]

Thanks Mark, Yeah. Taking it slow on this build. Still waiting on the PT/OT and trying to fill in some blanks.

That Aussie dude sure did a nice job on his build. Even got some praise from the Z man himself. I was hoping that there would be more posts on this thread.

I'll look forward to see some pics of your 2nd. build.

[M Fowler]

Yes he did a fantastic job on his wreck not sure I can build mine as well as he did but my second wreck will be closer to original.

[DustyBadlands]

Moving along slowly. Thanks to TAG members who clarified a few unknowns for me.


A friend who works at a local music store has a Z-wreck on order and will let me know when it arrives so I can test drive it.

[M Fowler]

That wreck is looking nice great work on the boards and layout. It will be complete very soon by the looks of it.

Mark

[paisley_tele]

What are the main changes from the rocket layouts to the zwreck?

[M Fowler]

Less main filtering with one 40uf.

Softer filtering using 8uf on B4 and B5.

The added 220k voltage divider on PI.

MF resistors.

Russian power tubes.

[FUCHSAUDIO]

Small Bear sells the knobs, as do many of the Chinese E bay people.

[DustyBadlands]

Z wreck Differences to the Rocket are,

1. V1 signal cap to volume pot is 470pf ceramic disc, Treble cap in tone stack is 47pf.
2. The 220k/220k voltage divider exiting the tone stack into the PI.
3. Long tail section - 976k R's instead of 1M, 47.5K R instead of 47K.
4. 250uf bias cap for power tubes.

5. B+ dropping string is paralleled from the output tube screen node to all stages and not in series as is the Rocket.
PI = 27k
CF = 22k
V1 = 27k

Input jack resistor to earth is also a 976k not 1M.
All signal resistors are 1/2w metal film.

The only other obvious difference is the way the CF stage is split between V2a and V2b, Not V1a and V2a.

[Zippy]

5. B+ dropping string is paralleled from the output tube screen node to all stages and not in series as is the Rocket.
PI = 27k
CF = 22k
V1 = 27k

Does that have a substantial effect on the plate voltage (idle) or is it more of an effect to isolate the effect of sag from the preamp?