Possible issue with Zwreck?

[Telewreck]

Hello,

I bought my Zwreck new about 8 months ago. I think it sounds decent, but there seems to be something missing. It seems to lack some punchiness and sounds kinda thin. I have tried 3 different sets of el84's ( JJ's, TAD's, and the original 7189's), that doesn't seem to make a difference. I have tried different preamps tubes in all 3 positions with no improvement. Someone told me it could be an issue with the PI socket. I looked into how to clean it, but the engineer in me wants to be able to measure something first, make a change, then measure it again. Are there any voltages I could measure on the PI that would indicate an issue. Any help would be appreciated.

Thanks,

Corey

[Phil_S]

Perhaps you can start by posting a full set of voltage readings...each B+ node and all tubes: cathode, screen, plate. A hi-res gut shot would also be helpful. What you describe, IMHO, isn't from a dirty socket.

[xtian]

You've been thoughtful and methodical with the tubes. Cool. Did you do the same with speakers/cabinets? What is your baseline for a good sounding rig?

[M Fowler]

Look at the back of the amp and flip the switch labeled comfort/speed.

Next look at the Trainwreck Files Section for Rocket look up various voltage charts lurking there.

Mark

[Blackburn]

You've been thoughtful and methodical with the tubes. Cool. Did you do the same with speakers/cabinets? What is your baseline for a good sounding rig?

That's what I was thinking when I read the OP. I LOVE GearManDude's demo of it and listen to it frequently. Great sounding amp in my opinion. I think speakers will make or break most good amps. Assuming you've eliminated all possible external issues, then get inside and start to tinker. I'd be surprised if it's internal.

[M Fowler]

If your Zwreck doesn't sound as good as Dave Baker's demo or other demo then I would contact Mike Zaite (DRZ) and send the amp in for repair after checking speakers, cables and guitar.

Mark

http://www.youtube.com/watch?v=TeXVHhN2I-U

http://www.youtube.com/watch?v=e3xyAeMyl3w

[Telewreck]

Thanks for the responses so far! I think there are three main demo's that I go off of; Paisley's, gearmandudes, and Dave Bakers. From what I hear of those, Paisley's and gearmandudes have an awesome ring/thickness to them that I don't hear with mine. I think mine sounds closer to the Dave Baker demo, but lacks a ring/thickness that the other two demos have.

I am new to tube amp inner workings. I would like to measure all the voltages first before sending the amp in. Are all the voltages for v1-v8 measured relative to chassis ground? One difference I noticed between the Zwreck and the rocket is that the wreck has pins 6, 7, and 8 jumper end together. Is that normal? Is there any schematics of the Zwreck anywhere?

Thanks again for your time helping me through this!!

Corey

[M Fowler]

The chime could be the use of either alnico blues or gold speakers.

The pins 6, 7, & 8 being unused Dr Z decided to ground them to make sure no noise was introduced.

There are no posted schematics for the Zwreck refer to the Rocket.

Mark

[Colossal]

Don't forget about Greg V's great demo of the ZWreck.
http://m.youtube.com/#/watch?v=YvBNcBed ... vBNcBedGfs

+1 for MFowler's comment; if your amp doesn't sound like that, return it for service. The Gold and Blue play to the EL84's strengths.

[M Fowler]

Greg V is the master of demo's. I didn't forget I was too busy
to look for it.

Mark

[randalp3000]

Don't forget about Greg V's great demo of the ZWreck.
http://m.youtube.com/#/watch?v=YvBNcBed ... vBNcBedGfs

+1 for MFowler's comment; if your amp doesn't sound like that, return it for service. The Gold and Blue play to the EL84's strengths.

send it back to the doc, I had an issue with mine also and they took very good care of it.
Mine was intermittent and a PITA for those guys. After totally rebuilding the preamp and a bad input jack turned out to be a flaky power trans.

Also I find the Blue kind of bright/thin and harsh especially when not broken in. Two Gold's sound wonderful with this amp to my ears.

[Telewreck]

I am going to have time tonight to check the voltages. I have a couple questions first.

I am assuming that I check the voltages with the power on, standby off (play mode), speaker plugged in?

If that is good so far, then I clamp the negative lead of my dmm to the chassis and with one hand in my pocket I touch the positive probe to each pin on all the tubes being careful not to touch any other pins at the same time. Is that correct?

Thanks again for taking the time to help me through this!!

Corey

[martin manning]

Yes, 7x.

[randalp3000]

This might be helpful. I think these were measured at wall voltage that could be a bit high like 123VAC. Here is a pic of the power supply, one more filter on the main board.

[Blackburn]

Nice! I'm surprised the reservoir is 40uf. I was expecting 80uf, like in the Rocket. Are there any other substantial differences? These amps do sound sweet!