I'd be grateful for a few words on how your "standard" build sounds which is what I shall begin with. My single reason for the build is to find out how the circuit will compare to the performance of my DIY JE Labs 76 Line Stage, active vs. buffered passive.
I tried the Schiit Saga+ with the single 6SN7 and was underwhelmed. I have a little box with an attenuator and switch from back in the CD intro days which sounded "pure" in the same rack with a 45 amp but in my current setup, a mismatch with 20' interconnects to KT88 monoblocks. The amps have the negative feedback from the Mullard circuit removed, so as wonderful as the 76 Linestage sounds, a passive is enticing to try.
Khozmo volume control, hmph! I went one step further and bypassed the volume pots in my B1 completely. You don't get clearer than that.
I need the volume pots, as I don't have any such control elsewhere in the system. But yeah, I get it.Khozmo volume control, hmph! I went one step further and bypassed the volume pots in my B1 completely. You don't get clearer than that.
These two B1s are balanced: Two boards, one for each channel. (I am in an RF/EM heavy environment so need balanced interconnects, and mine are 40 feet!) So that probably makes some difference, as well. But it's really impressive, even compared to my Pass XP-20. I guess the main thing is just how transparent it is, which is expected, but in a way it takes some getting used to. Sometimes it can sound a bit 'dry', if that makes any sense. It's certainly not always like that, but comes and goes with the recording, so I've convinced myself that that's just what the recordings themselves are like.
I'll be curious, actually, to see what effect the H2 second-harmonic generator might have, but I haven't had time to build that yet.
I've built both the H2 V1 and V2. The H2 sounds a bit clearer than my "standard" DIY B1 with dubious caps, but after the ClarityCap upgrade, the B1 wins hands down. This is just my opinion and with a DIY B1. YMMV.
They were Vishay MKP and ERO MKT - the best I could find locally with my limited experience at the time. The B1 was my first DIY audio project.I’d be interested in what caps are the dubious ones. Cornell Dubillier?
Picture of the caps in post #4968.
Interesting! I’ll check out your post. Will possibly build this buffer. Long time overdue, but needs to be tried. Thank you!
Is it better? And if it is, why did Nelson use the caps? Are they there just in case your source produces DC offset so that you don't fry whatever's after the buffer?
If so, does it mean that it's absolutely safe to remove the C100/C200 caps if the next stage has its own decoupling cap?
More pics of my B1 in post #1610.
Remember that the B1 PCB + matching Jfets is still available at www.passdiy.com/store.
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We've found experimentally that SMPS switchers come in all sorts of levels of quality but also in their ability to push through both both various R and especially C loads. Having built most of Papa's preamp variants over the last few years and and explored this about a year ago when the switcher we chose (that differed from the specified Triad) for the ACP+ kit failed to push through the empty caps on the input side. Basically I've found that you need to start by checking the spec sheet of the SMPS in question and even then, many simply do not list their ratings for capacitive loads so YMMV.
This is why on these projects, I'd strongly advise using the supply that the designer specified unless you really know what you are doing. As @6L6 likes to always say, build it by the book first and get it working and only then start experimenting from a stable point. In this case, use the specified Triad and if everything works, you know that the new SMPS you introduced is the culprit.
No, B1 is using single rail supply. You need to use symmetrical power supply to have zero dc on the output.
https://www.diyaudio.com/community/threads/building-a-symmetrical-psu-b1-buffer.145201/#post1854512
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Yes that is the one. Mezmerize with a name nobody seems to be able to write correctly. Named after a song by SOAD:
https://en.wikipedia.org/wiki/Mezmerize_(album)
No coupling caps, no SMPS, onboard linear shunt PSU (!!!), onboard source selection with relays, 6 inputs, onboard volume control with a stereo potentiometer, moderate cabling/wiring, power on/off muting with a relay, single board design. Better in all aspects. Sorry
https://en.wikipedia.org/wiki/Mezmerize_(album)
No coupling caps, no SMPS, onboard linear shunt PSU (!!!), onboard source selection with relays, 6 inputs, onboard volume control with a stereo potentiometer, moderate cabling/wiring, power on/off muting with a relay, single board design. Better in all aspects. Sorry
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I've been thinking about building the Mezmerize. However, has anyone ever rated the preamps for sound quality? E.g. how does the Mezmerize compare to the WLS (Wayne's Line Stage) and other DIYStore offerings?
These questions have been discussed earlier in this thread. The rationale for a single rail supply is that it's much easier to source and set up power supplies than a dual rail (YMMV), and this buffer was targeting the more general DIY crowd. C100/200 couple the input to the JFETs, and if there's DC there from the source, wouldn't it mess up the gate bias of Q100/200? But were you talking about C101/201? I'm pretty sure the latter block the JFETs bias DC from going into the input of the next stage.
Edit: I like that I was able to build my single rail B1 buffer using a cheap wall wart, rather than a fancy linear supply. In fact it was the same cheap wall wart that came with my B1 Korg kit, which I no longer use, so I didn't have to hunt for a new one. This same cheap wall wart also allowed me to play with the effect of a PO89ZB filter, and saved me from finding a new chassis that would also accomodate a toroid and a linear PSU. And it also.... allowed me to play with the effect of output capacitors, ahahahaha!!
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