Jensen or Mundorf coupling capacitors?

[timm]

Well got the 98 back today. It has been playing 4 hours and I can hear it opening up. Out of the box I heard a difference - in particular the bass. I will hold judgement but I think it is gonna be reeeealll good.

You think 100 hours for new output cap / direct coupled/ hexfreds/new caps in power supply??

[decooney]

Good for you. Glad you got it back and its working out.

You'll hear changes at 40-50 hours and again at 100 for sure. Seem like mine settled after that but I got impatient and started NOS tube rolling at that point.

What tubes do you have in it now?

[timm]

All I have is the brown base Chinese tubes for the 6sn7s.

It is sounding pretty 'marvy' right now actually. My first impressions are way improved bass .... musicality... more body and texture ( didn't lose its tube character) Now, based on memory - the pre had less of this than the dac going direct before. When I went direct dac to amp - the sub was disconnected. There is absolutely no need to hook it back up with the pre now and everything I mentioned above - I feel give it the leg up vs going direct. I'll do a direct a/b - but afterbreak in. I having too much fun right now. Haha.

[decooney]

Originally Posted by timm

All I have is the brown base Chinese tubes for the 6sn7s.

It is sounding pretty 'marvy' right now actually. My first impressions are way improved bass .... musicality... more body and texture ( didn't lose its tube character) Now, based on memory - the pre had less of this than the dac going direct before. When I went direct dac to amp - the sub was disconnected. There is absolutely no need to hook it back up with the pre now and everything I mentioned above - I feel give it the leg up vs going direct. I'll do a direct a/b - but afterbreak in. I having too much fun right now. Haha.

Yeah, I don't like going DAC direct even though I do it for a second amp and second set of speakers for a different use. Having the upgraded SLP98 in front of my DAC makes for extra tube magic. Wait 'til you start rolling some different 6SN7s later on. It helps it to sound let's say "different"... however, if you like it now with what you have, keep letting it burn in as-is with your current tubes so you can discern the difference between the upgrade benefit and not confusing oneself by prematurely rolling tubes like I did, but then again, you can always go back and put the original tubes back in too. I did find the upgrade made as much if not more difference than the tube rolling OR let me say this, the tubes, new or NOS started to come MORE to life after I did the SLP98 upgrades.

Have fun

[timm]

Fought a bit of a ground loop issue tonight. Grr. Ended up moving the power supply on the same circuit as everything else. So far so good. I find this pre a bit sensitive. Guessing most tube units are.

So I have heard good things about multiple 6sn7s - do you have any experience with the sylvania chrome tops/ cbs hytrons/ or RCA tubes and what each does?

I will be patient.

[decooney]

yeah, and tube changes are usually after the caps and bits are burned are you at 40-50hrs yet? Also, before changing tubes, what interconnects do you have between your preamp and amp, and what cables between your source an preamp?... how much syrup do you need on those pancakes, taste varies.

I settled on the vintage NOS Sylvania Black pates. Formerly tried the RCA Reds base prior to that and they were kinda fun, had a little more break-up sooner. May go back to those in the future but like all the Sylvanias at this point.

[timm]

Probably have about 20 hrs on it so far.

I've been battling a ground loop I'm pretty sure. I tried a power cord that was 2 prong male/ 3 prong female on the 98 and blew a fuse on it. Went back to my ginormous power cord. When directstream dac is connected to pre - that seems to be the issue. I have used a cheater plug on the DS and all is well so far. I'm going to talk to Marc at Cary on Monday. Do you get hum from your power supply? I'm Getting a little.

My interconnects are audioquest king cobras for amp and source.

The sound overall is still reaching fantastic. I really can't wait to a/b it against direct. That is the only way I'll be able to get a true delta on the movement as direct had more heft before - and I don't think that is the case now. Getting there. Right now - I just don't want to unplug another interconnect / cord etc.

[decooney]

Originally Posted by timm

Probably have about 20 hrs on it so far.

.. Do you get hum from your power supply? I'm Getting a little.

...- I just don't want to unplug another interconnect / cord etc.

I gave up a while back searching for (intermittent) hum between incoming cable systems and other equipment. While I could reduce it substantially, and I started to run dedicated circuits, the same thing can occur. Garbage in creates garbage all around. I finally removed my monster power conditioners and replaced them all with a really good Richard Gray Power station. Now it stabilizes the entire circuit and the other wall plug on this circuit. Much better now. Should have done this a long time ago.

[timm]

So -- things are sounding fantastic... I will need to hold off my final 'review' of the direct coupled pre.... because of an issue I am having... So - It seems like I can rid myself of the hum mentioned above by using a cheater on the dac....

When I sent the unit in - it blew a fuse initially - and that is why I sent it in (fuse looked fine to me - but 'Duh' it was not) .... anyway - so they put in a fuse - tested it ... and it was fine in their office/testing....

It comes home - and after 3 days or about 24 hrs of play time - it blows a fuse in the power supply ... Well I figure - it was in transit.... About 2 days later it blows another - again after substantial play time ....Then a third several days later.....

So I am not here to bang on anyone - Just trying to figure a good approach to figure out 'what' it is....

Right now - I am letting it run - non-stop without outputs or inputs.... Going to do that for 3 days.... Next I will at my amp..... let that go for awhile .... and finally add my dac back....

Can a bad or misplaced tube cause an issue ? I'm not using the phono stage - could a 12ax7 in a 12au7 slot cause this possibly in the phono stage? (I have this - which I noticed when I got it back... uh... I couldn't tell you whether I sent it that way or not honestly.. maybe ... but I would have thought I would have noticed this after 5 years of ownership...and when I was placing it in the tube box for shipping - but the tubes do look identical) Nobody mentioned this when the pre was in for the fix.... so maybe it isn't really a big deal... but... Since this seems to be a 'slow burn' I am investigating anything....

I have an after market 10 gauge power cord on the power supply.... I am connected directly into the wall ... have no other issues with other equipment... live in a house built in 2002 ... in a good neighborhood... (i.e. I would think the inbound power would be good - and have no issues with anything else)

I am using the 1 amp slo blow fuses that Cary sent back with the unit....

Any ideas ? Any thoughts on testing to determine what might be blowing the fuse? I think the tech at Cary thinks that it can not be anything related to output per se - especially since it is happening in the powersupply downstream from everything....

If it rolls fine with nothing connected - is it possible that connecting an output or input could cause the power supply fuse to blow?

Like I said - other than this - the unit sounds great....
All help or suggestions appreciated....

[decooney]

When you unplug/plug in your devices (one at a time), have you figured out which one causes humm first? When you find it, measure the voltage on the RCA interconnects, what do you get?