[Ori]

Quote:

Originally Posted by cheezx /img/forum/go_quote.gif I've been reading about the bypassing cap mod and would appreciate it if someone showed how that is done. I've seen the picture posted above, but I'm not sure if that's the A or C version.

Both versions include the same output board, so the mod is the same.

 

[cheezx]

Oohhhhh, that makes so much more sense now. Thanks!

 

[dviswa]

The cap mod consists of shorting out the 4 largest electrolytic (neon green) caps on the analog board right?

I did it and there was definitely a welcome improvement in sound and after some time, something else happened, which was definitely not welcome. Oscillations! I had never seen it before. So I cut the shorts out and mounted the board back. After hooking back, the oscillations were back. I shook all the connectors and the oscillations have gove away for now, but we will have to see if it will back. Not sure if the oscillations were due to bad contacts in the connectors or not. The oscillations consisted of the clock getting messedup, playing at erratic speeds and sound being very choppy.

Has anybodylese seen this before?

 

[udo]

Quote:

Originally Posted by dviswa /img/forum/go_quote.gif After hooking back, the oscillations were back. I shook all the connectors and the oscillations have gove away for now, but we will have to see if it will back. Not sure if the oscillations were due to bad contacts in the connectors or not. The oscillations consisted of the clock getting messedup, playing at erratic speeds and sound being very choppy. Has anybodylese seen this before?

You modded something in the analog domain and the (digital) clock goes haywire?
Are you sure of the observations?

 

[dviswa]

I hardly said modding analog section resulted in clock going haywire. My suspicion is on bad connectors. Perhaps the ground lifted or something. Don't know. I am going to short the caps out again today.

 

[dviswa]

Did the mod again. So far it seems to be well behaved. Let's see.

It is surprising how much imact the caps have.

BTW, from a cost/benefit perspective this has infinite benefit, afterall cost is zero

 

[cheezx]

Just did the cap mod and the bass has definitely improved, less mushy and more...direct.

I'll need more time with it

 

[jholtz]

I rolled opamps and shorted caps with good success but it still wasn't giving me the sound quality level I'd hoped for so I installed a Zapfilter. The sound quality is excellent on most recordings with incredible detail. The sound is extremely smooth and almost analog sounding with lots of air and a very defined image.

However, you knew there was a however didn't you? On a number of recordings, the detail is great enough that what sounds like the added ambiance sound studios add is congested or strained sounding for lack of better descriptors. It seems to be primarily on female vocals but some jazz CD's that are instrumental also suffer from the congested background sound. The CD's sounded fine before the Zapfilter install which has me a bit baffled. I switch to a different CD and the sound is crystal clear.

Has anyone else experienced this after they installed the Zapfilter?

BTW, this is all based on listening through speakers. I have Selah Audio line arrays which are extremely revealing.

Thanks!

Jim

 

[Crow]

Quote:

Originally Posted by jholtz /img/forum/go_quote.gif ..... the detail is great enough that what sounds like the added ambiance sound studios add is congested or strained sounding for lack of better descriptors. ....

It's amazing, isn't it? I have a ton more CDs in the crap-bin because of this. If the recording isn't just A-rate perfect, you become painfully aware of it. Sort of a mixed blessing, but now I'm hooked and could never go back to being un-zapped

Cheers & Enjoy

 

[jholtz]

Quote:

Originally Posted by Crow /img/forum/go_quote.gif It's amazing, isn't it? I have a ton more CDs in the crap-bin because of this. If the recording isn't just A-rate perfect, you become painfully aware of it. Sort of a mixed blessing, but now I'm hooked and could never go back to being un-zapped Cheers & Enjoy

Hi Crow,

Thanks for responding. You have just confirmed that I'm not alone in hearing this. Accuracy I can live with. I was afraid I'd done something wrong.

I must admit, the Zapfilter install has turned the Zhaolu into the most detailed DAC or CD player I've ever heard. It's phenominal. It does have the downside however.

Thanks again!

Best regards,

Jim

 

[flashnolan]

Wow made it through the entire thread...it only took me about two weeks a few hours a day.

 

[El Condor]

Quote:

Originally Posted by flashnolan /img/forum/go_quote.gif Wow made it through the entire thread...it only took me about two weeks a few hours a day.

Hehehe, and that's all you have to say about it?

 

[jholtz]

Quote:

Originally Posted by Crow /img/forum/go_quote.gif It's amazing, isn't it? I have a ton more CDs in the crap-bin because of this. If the recording isn't just A-rate perfect, you become painfully aware of it. Sort of a mixed blessing, but now I'm hooked and could never go back to being un-zapped Cheers & Enjoy

Crow,

I meant to thank you in my previous response and forgot about it. I used your detailed post with links as a guide to the Zapfilter install. It was invaluable and I really appreciate your contribution and assistance.

Best regards,

Jim

 

[Crow]

My pleasure, jholtz! Always happy to help another head-fier deeper down the rabbit hole. Warm fuzzies....

Cheers,
Scott

 

[dmcgown]

I have the Zhaolu 2.5C with the CS DAC, and previously have done a few mods, including the basic bypass of the DAC coupling caps, using LM4562 op-amps, and using Schottky diodes in the power supply. All have improved the sound over the stock unit, and was very satisfying, musically and sonically.

However, today, I put together a replacement output stage consisting of a of CineMag CMLI-15B 1:1 transformer for each channel coupling the differential DAC outputs to single ended feeding to an Intersil HA5002 buffer, which is direct coupled to the output. No capacitors, the transformers have a similar bandpass as the original filter network, so no anti-aliasing filter required.

The sound is incredibly open and clear. The microdynamics are another level over the previous mods, and I am hearing low level detail I have never heard before in digital. I do not have a circuit diagram to post, but it is conceptually simple.

This is a simple but worthwhile mod, the only drawback being the cost of the transformers (~$100, direct from CineMag). However I feel this takes the unit to a pretty high level of performance.