Help and Advice Needed: Cary Audio SLP-05 Preamp RMA Disaster
First, I want to thank everyone. This forum has been one of the best sources for information about gear, and I have used it extensively for years.
I am in need of help and advice on how to proceed from here.
The preamp is a Cary Audio SLP-05 Ultimate w/ Kimber Kable Upgrades.
Does anyone have an issue with the volume on their SLP-05 not fully muting when the knob (not mute button) is turned to zero, and do they have significant crosstalk between the channels?
This is only with XLR in and XLR out.
In particular, I would like to hear from people with DAC's with a rated voltage of 4.5V or more on XLR. This is about every high end DAC like the Holo, Chord, Auralic, and even Cary offerings, as well as DACs from Matrix, and other entry level high-end DAC's
My Gear:
i9 based server running HQPlayer Embedded and Roon Core.
Sonore Optical Rendu, Holo May KTE DAC, Manley Snapper Monoblocks, 6Pi Cornerhorns.
The story is a bit long,
so here is a TLDR;
My SLP-05 preamp does not mute when the volume is turned to zero (mute button works fine), and has significant cross talk between channels. I can input a 1KHz test tone into the LEFT channel (not other inputs), and hear it clearly from the RIGHT channel with the volume turned to zero.
Here is an unlisted video that I sent to Cary demonstrating the problem.
Cary is claiming the issue is my gear. First, they claimed my amps have too much gain (it has less than the Cary amps), and too many watts (watts?!?), then my speakers are too sensitive (102dB). They finally fixated on my Holo May DAC having too much voltage at 5.8V on balanced (the Cary is rated at +/-3V, or 6V). They remained fixated on this even though I provided the above video using the Matrix DAC which is rated at 4.5V.
I measured the voltage coming out of the Matrix DAC as shown in the video at
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pin1-pin2 |
pin1-pin3 |
pin2-pin3 |
|
Matrix DAC LEFT |
1.085V |
1.084V |
2.170V |
|
Matrix DAC RIGHT |
1.083V |
1.081V |
2.164V |
which is very close to what they claim is "standard."
Cary is being resolute in stating that they have sold thousands of these preamps, never had this problem, and my case is unique. It seems I am the only owner of a Holo May (or Chord, or Auralic, or...) and an SLP-05...
Advice needed:
Cary is proposing modifying the preamp as follows:
1) Relocate a capacitor that is getting charged via the ground plane near the input buffer tube, and isolate the input buffer ground.
2) Tie the floating XLR neutrals to ground at the relays (this will short the inputs when an input is not selected).
3) Add a 5:1 voltage divider across the input for XLR 1, and RCA 1 to reduce the inputs from 5V to 1V. I do not know what they propose to use for the ground reference here.
I would like some feedback on these mods. I think some of these are pretty questionable. Why tie the relays directly to ground when it might be better to tie them through a 1M resistor? Tying the XLR neutral to ground seems like an invitation for common mode distortion and might prevent the circuit from being fully differential.
Moving the cap seems fine, but it does not address the core issue - why are we having ground plane issues in the first place?
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The story as briefly as possible
I want to be clear up front, that I never engaged in raging, yelling or name calling, I never made any demands other than "you have to make this right." I did express myself as being "very upset and angry," and in a later email, "Please understand that my trust is pretty much gone at this point."
I RMA'd my 2 week old SLP-05 because the volume would not fully mute with the volume control (mute button works fine). While they had it, I paid ($250.00 + $250.00 shipping) for the gain reduction mod.
They could not find anything wrong performed the gain reduction mod, and sent the preamp back to me.
When I powered on the preamp, it was DOA. It turned out FedEx dropped it hard enough to knock the rectifier tube loose, and break the straps holding the big power capacitor down.
I found the gain reduction had no effect that I could determine, it is too loud at 10:00, and almost impossible to adjust to a low listening level.
I found the signal still bleed through at zero volume, and I found that the left channel bled through to the right channel.
What ensued was a steady stream of what can only be called BS (or "nonsense" as I referred to in my emails) with the Quality Service Manager. When it became clear that not only was I being not being listened to and there was a lot of CYA going on, I called and asked for the contact info of someone in authority to monitor the situation. I was given the email of the owner, who it turned out was never told about the shipping damage. I was finally issued an RMA 3 weeks after getting my preamp back.
They once again could not find anything wrong.
I had to actually write out an experimental plan for them to duplicate the issue.
As far as I know, they did not test another preamp with or with out the upgrades to see if the issue is unique to my unit or not.
It is clear to me that Cary does not want to know if there is a problem.
I am at a near loss as to how to proceed from here, and I could really use any input you good folks could provide.
Thanks you,
-Josh
While it might be implied here somewhere, going to ask anyhow just for grins. Have you tried this exact same test with a different dac using SPDIF digital coax out to your Cary SLP-05 preamp - what happens?
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@joshua43214 Gotcha. Insufficient validation testing and shipping damage, would be frustrating for most anyone. Not the first time a combination of components, XLR, and a few things together produce a "unique" situation. It happens. One thought, hypothetically - let’s say if Cary implements recommendations 1,2,3 above, and they now have (finally) proven the ability to replicate the issue, can test for it now, and the fix works, why would you not do it after coming this far. Asking IF they can also test and prove suspected ground issues no longer exist. It's curious they already have these recommendations, I figure those did not come up out of thin air. Interesting. If you wanna take it to another level, send your dac too for testing. I'd bet there are other Halo DAC owners with SLP-05s out there. . Maybe ask about the grounding questions/concerns over the phone too, before sending anything back and forth again. It’s also possible they may have challenges with testing the same scenario if they don’t have 102db efficient speakers lying around. Your demo videos are smart. Maybe they can do the same at their end, showing you how it tests and works [with agreement] before they send it back to you again. Best of luck.
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Huh - confused - How so? Were details shared about how they were able to replicate the issue? |
I’m a Cary Audio owner as well with three prior amps and preamplifiers with no issues, all of them with upgrades before and after purchase - knock on wood. Have encountered many proud SLP-98 and SLP-05 preamp owners, hoping this situation could be rectified for the OP to get back to listening enjoyment. Not the first lemon story or with shipping damage though. Hopefully this can still be resolved with persistence and a few more steps or a return if warranted. |
@gs5556 exactly, I brought this up earlier and OP went right back to justifying XLR again instead of re-evaluating this as a serious option, look for lower-gain source and preamp gain particularly with high sensitivity speakers. Try again with RCA! |
@joshua43214 I was reading an application used with Kimber XLR and one ground wire used thus allowing noise. Earlier, was attempting to understand if you only experience the noise issue with XLR only, and not with digital RCA coax. If you already stated this or someone else did, I missed it. Agree it should hopefully work for the price you paid, however something in the chain of components is pushing capability beyond the design limit, it seems or maybe the cable is a contributing factor. I was wondering if the use of XLR was elevating the voltage somehow inherently by by design. I had gain with subtle noise in my former SS preamp and amp and defaulted back to RCA for signal, just for this reason alone. One other XLR I tried did help some. Just for grins, by chance have you borrowed or tried a different shielded XLR cable design with a different type ground configuration to eliminate the cable itself as a potential culprit? |
Yep. Reading a test on the Halo May showed this, "The May's maximum output level at 1kHz in NOS, OS, and OS/PCM modes was 5.8V from the balanced outputs, 2.9V from the unbalanced outputs." Looking over my current two DACs and prior three units, all of them are 2-3 volts max output. The question i'd be wondering about is repeating the same test with another unit outputting 3v or less, and a different pair of shielded XLR cables. Or, put the XLRs aside and run unbalanced cables for input/outputs and start listening to music.
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In this case, and with this type of remedy, do you find that introducing an attenuator into the signal path degrades the signal, thus rendering the whole idea and benefit of XLR connectivity to be sort of self defeating? And, in this scenario have you truly compared RCA to the attenuated XLR approach and compared what actually sounds better to you? My local 53 year audio shop runs a lot of AudioNote and other sophisticated brands, SET, Triode, wonderful sounding gear. He’s had it all. None of it is XLR is why I bring this up. He only believes in XLR for longer runs beyond 15-20ft in most cases, fwiw. |
@mm1tt77 I don’t disagree, and it does vary by design where more emphasis can be placed in one direction or another. Some of my prior fully balanced dual mono amp gear offered XLR, and my current DAC offers XLR,. However after careful listening I’m using RCA for input on digital coax and RCA on output to/from the preamp to amps and it sounds more natural to me, not boosted with unnecessary voltage gain with consideration of my speaker efficiency and room. The better preamps I've tested are also low gain too. Results can vary of course. Best of luck and happy listening. |
In your case and components, you know what sounds and works best. The only thing that matters. Has Cary Audio stated what the allowed maximum input spec is for components plugged into your SLP-05 preamp given its current design? Did you see this, not sure if someone brought it up earlier - JA's review of the SLP-05 and test results including balanced and unbalanced connections.
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