Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp - Page 576

There shouldn't be caps there at all in the signal path. Are you using the HP amp built-in or another amp?

I've tried it both ways. When not using the built-in amp, I'm using a LD Mk V.

You could try different opamps. If you're up for some rather tedious disassembly work, you can also roll the opamps in the MKV and even fit HDAMs in there.

Maybe I wasn't completely clear. There are two 22pf caps in the signal path near the RCA outs. Some suggest that removing these adds detail. I tried it, but it's too bright for me. I should have left it alone. I purchased replacement caps but it's still a little too bright.

Would 100pf caps sound different than the 22pf caps?

I think we all understand but the fact is those caps should offer a minimal change at most - many say they shouldn't have been there in the first place. I'm no expert but my guess is that an opamp switch would do more to get what you want. Just replace the caps that were there if you don't like the change, and look at some opamps to back off the brightness. Of course I could be very wrong...

If you think its too bright then you'd do well to swtich the opamp on the DAC. Pop in something smooth, like Moon HDAM.

Hi ScottieB, I just want to add an observation here to what you posted. I'm thinking that most of the Initial OpAmp evaluations were made with these Caps in place. It is quite possible that a second look at the OpAmps with the Caps snipped would reshuffle the preferences of which sound best?

What do you think?

A lot of folks like them snipped, I left mine in place.

Could be... I'm finding more and more that I tend to like the "bright" or "forward" sound. My first "good" headphones were Grado's so this is likely where this comes from. My current cans are Senn HD-600, which are much darker. Overall I like them, but I tend to enjoy it when I can bring back a bit of the brightness I left behind with the Grados - so the snip mod was great for me and I enjoy the Sun HDAM as well with my Senns. Just trying to find the best of both worlds I guess - and i seem to be getting closer.

More along the lines of what you were saying, when i first tried them, i wasn't a big fan of "the russians" - tubes for my LD MKIII, but now, with the snip mod, the Sun and the HD-600s, I am actually liking them a LOT - especially with rock music.

So yeah, I think your perceptions of all the various changes you can make may be altered by the OTHER mods in place... makes sense. Whether you like the cap mod and what it does to the sound definitely has something to do with your affinity (or lack thereof) for brightness. Put another way, everything has to work together to give the sound you hear - headpohnes, source, hdam, cap mod, other mods etc - so changing any one thing in that loop will likely (at the very least) color eveyrthing else in the chain, no?

My Zero Died

Well my second Zero died after about two months. I received it early November (from wsz0304) and it was functioning perfectly fine since then until a few days ago I got no output. I noticed that I was getting signal lock (the LED lit up and the relay clicked) from both coax and optical, however I was not getting any signal from the RCA ports in the back or from the HP amp. I verified that the HP amp is still working by testing it in a spare Zero I have (my first DOA Zero from Lawrence that had a bad HP amp but a good D/A board, so I could use it to test). I have not done any modifications whatsoever to either Zero nor do I notice any obviously burned components. Pretty frustration, but at least others have said that wsz0304 takes care of these things pretty quickly and often without making the user send back the component. Even if I have to send back the component, it should only cost about $10 (assuming I can box the D/A board up in under a pound). Not trying to complain to the forum (I have done that enough already about my Zero troubles), just trying to update others on the incidence rate of failure. Latent failures are scarier than DOA because it could occur soon after the 1 year warrantee period.

I would often leave the Zero on (without signal) for several days. Supposedly with SS equiptment this should be ok (maybe even better than cycling the power so often), so it is not an excuse for such failure, but with the Zero it might be something to keep in mind. The Zero might not be properly designed to handle the heat it produces.

That Sux! Thanx for the update. I leave all my SS stuff on all the time. Have always done that. Have you tried an OpAmp swap out? Or a Transformer swap. The one good thing about two Zero's is having swap parts I suppose.

I didn't spend the time isolating the defect to an individual component, I just know it isn't the headphone amp because I tested it on the other system. I doubt it would be the transformer since I am getting power and even digital signal lock in. Hopefully I will get the replacement d/a board from wsz0304 so that I will have a spare. I previously had the notion of selling the other Zero with the bad HP board to someone interested in using it for its RCA output but now I think it might be worth just having the spares around.

Good to have spare parts around, there's something wrong with the silver lining in this cloud, ehhh?

Most Zero owners don't have spares. Keep it around. I'm, one of these days, going to do my Franken mod. I am at risk of burning it up. If I do, you can have my HA board. I'm going to mod it first and test it, so it should be good to go. I'll probably hose the DAC board when I start goofing on it.! Keep your fingers crossed!

I've finished the frankenZERO mod.. and... somethings wrong
I dont hear the sound through the zero amplifier and i dont have anything else like speakers or another ampliifer to check which part of zero is wrong. 4 led red diodes are ON, i hear quiet noise on headphones, so amplifier should be ok.
When i press the reset button, i hear for a half of second a sound through headphones.

help..

That's rough, I've got no idea how to help you troubleshoot. You should post in the FrankenZero thread and see if peete or some of the other mod guru's can help you out. The first thing I would do is check over visually all your solder joints. You can use a Volt Ohm meter and make sure your solder joints are not open. Pay particular attention obviously to areas that were difficult for you to desolder or solder. You may have got something too hot.

it's horrible.. no idea what went wrong. I talked with Peete, i think all parts are in good shape, they are ok. Probably i made cold solder joint, or track is cut somewhere. Tomorrow im taking my zero to electronic service. I dont know how to find mistake. Even if i look on solder, i dont know if its cold or not