Sold a perfectly functioning zrock2 and the buyer (Andrew) just got it.

The tube lights but no signal coming through when the front switch is in the up position.

Anyone ever have this problem… Steve?

Thanks for any help troubleshooting.

John

Thanks for starting this, Johnny.

I'm getting audio when the ZROCK2 is in the down position (bypass).

When I flip the switch up, the audio drops out.

Thanks will i asked the person the same question about interconnect orientation and whether tube was fully seated which Andrew confirmed.

Could the tube light but still send no signal through?

When I got the unit the tube was humming, so I replaced with nos organ grade which I supplied with unit as sold.

Thanks John

Thanks, wish a tube was closer at hand for him to swap.

Thanks again.

Hi Drew.

It appears from your equipment signature, that you are vinyl only?

But, if you have a digital source, you could take the 12au7 out of the ZP3 and try it.

Best,

Geno

But, if you have a digital source, you could take the 12au7 out of the ZP3 and try it.

Hey Geno,

That's correct, I'm all vinyl. I was able to borrow a 12AX7 from my Mesa Boogie Lone Star.

Unfortunately, the problem is still present. When I flip the front switch up to the on position, the signal drops out. The audio can be heard verrrrrrryyyyyy very faintly in the speakers.

Definitely not operating like it should as shown in this demo:
https://www.youtube.com/watch?v=LfbGUBaofAM

Once I tried a 12AX7 in my ZROCK2 and no sound.

Sounds like a replacement 12au7 might fix it.

Hey Drew. A new toy and no play. I feel for you (and Johnny too).

One thing that occurs to me that you likely tried also... Have you tried it with the "A-B" switch in the back in the other position? If it happened to work, I think that would rule out the tube circuit anyway.

Have you tried it with the "A-B" switch in the back in the other position? If it happened to work, I think that would rule out the tube circuit anyway.

Yeah, I tried that too. No dice. Added that to my list above, forgot to add that.

Sorry Drew. I am bad not to reload the page before posting, so I did not see your test method post before asking about the back switch. Glad you found a tube to test with.

In my first version of the ZRock2, with the tube mod only, I preferred 12AT7s for the most part, at least a very sonically balanced and resolving one I have, a particularly complete sounding old Mullard. After I fully modified the ZRock, fine tuned with faster, more transparent parts and wires, and some pretty complex cap bypassing... a 12AU7 is very resolving and plenty dynamic for me. 12AT7s are still more powerful, so bigger, denser and more vivid seeming... seductive for a while, but so far they seem to have moved into an overstated zone for me... in this system anyway.

May be a little different for yours, but on my ZRock2+ version unity gain is below 12 o'clock with a 12AT7, like 11ish, and with a 12AU7 around 1 o'clock give or take.

Turnaround is generally two weeks or so.

Maybe there is a ZRock virus going around

So you’re actually seeing your tube’s glow disappear, Cliff?

If so, that’s not what I’m seeing. All three tubes I’ve tried are glowing strong and never fade out.

This is the response I received from Steve, “ The symptoms you describe are exactly what happens when it is hooked up in reverse. The vertical pair of jacks nearest the outside edge are the output jacks while the inner pair are the input jacks. Another possibility is the fuse holder contains two fuses, a spare in the square tunnel and the active fuse in the clip.”

Unfortunately, both issues he mentioned aren’t the problem. One fuse and the cables are 100% in the correct jacks.

Verified with another power cable. All is good.

Hi Drew

I see that Zrock was described as having tube regulation. Could it be that shipping could have damaged that tube located inside the Zrock?

John

great catch jbzen. I had completely forgotten about the internal tube while working with Drew, but I guess it's not that either.