Interesting. I had a “noisy” tube in my BHK pre and all hiss and static went away when turned to 53.
Perhaps true, but unfortunate to think of it that way. Bring out the internal scientist in you and think of it as an enjoyable experiment. Life isn’t always simple. But it does seem odd to this simpleton to need to tweak two things in the signal path to get the desired volume set.
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One can easily set volume with only the preamp or the DAC; i.e., there is no “need” to use both to set a given volume.
But precise gain staging always has benefits and having a DAC with a lossless volume control provides wonderful flexibility.
It’s just set and forget, right? You just set the volume of the DS DAC somewhere in the mid-point between those notchy BHK PRE volume values so you can cruise up and down the volume scale without any snap, crackle and pop?
That’s one option.
Or, if you are like me, the little minor noises the preamp makes at times are of no concern.
Many possibilities based on what works for the individual user.
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This is your equipment to use as you wish. I never lend my ears or brain to someone else. If 100 on DSD works great… run it… you paid for it… take it out for a spin. If you like to use the both pieces of equipment as a volume adjustment, Paul will give you a hug cause you bought both from PSA. If you don’t have any PSA gear… just read along and make comments as you wish… we have filters… it’s all good… water is warm… jump in and lather up…
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Except that, some people here don’t like people making comments about gear they don’t actually own.
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Depends on a number of factors and opinions. For me, using the DSD balanced into the BHK preamp there’s no contest. BHK volume control is the way to go.
Your mileage may vary.
Apparently I don’t understand it. In the various discussions about noise within the equipment, we accept that the biggest noise comes from a volume control on our PS audio pre amp. It just doesn’t hold. I call it the best one ever built. Then I do not want to experience the worst. Why do they make the high 0.5 dB step clicks?
Hi Michael!
Greetings from Sweden 
The clicks comes from differences in the two amplifying halves in each tube. If they are perfectly matched, no clicks. I have an Orange Valve/Tube meter that I test all tubes in, and it verifies this.
/Mats
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Excellent observation!. Consistent with my own with one caveat - perfectly matched triode halves is darned near impossible to achieve in practice. That said, while I don’t have my own tester, I only use tubes in my BHK Pre I know have triode halves matched to within at least 5%. All legitimate tube vendors will offer tube matching and the trick is to ensure tube matching goes beyond tube to tube and includes matching of the triode halves of each tube.
This is why beyond a very faint click I can barely hear when I slew my volume, I have never experienced the more extreme issues some have reported on the forum.
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Just bought a new Pass Labs X-250.8 amplifier to replace my trusty, but old, White Audio Lab amplifier. The White Amp is 100 Watts of Class A amplification. A nice warm sound, lacking a bit in the bass, but a damn good amp that I loved for nearly 3 decades. I had the White Amp in line with a ARC LS2 pre-amp for years. The volume control from the ARC to the White was dead quiet, though when the ARC turned on I would hear a Pop, subtle but there.
So then I put away my ARC and used the DS Jr direct to my White Amp. Volume control was dead silent, but I had other issues - the DS Jr just wasn’t driving the White Amp, bass was at it lowest, things weren’t totally right. So I bought the BHK Pre and everything opened up again, best sound my stereo had to that point. The only downside was the clicking volume as I turned the dial of the BHK Pre. Annoying but I could accept it because I really don’t fiddle with the volume much and once set it would usually stay. The only real trouble was turning the Pre on and off, then I’d get a loud POP!
So now comes along my new Pass X-250.8 connected to the BHK Pre. Twist the volume knob on the Pre and DEAD SILENCE. Turn on the Pre and no pop whatsoever. There is only a very subtle pop at 24-25 and 52, but you really have to listen for them to hear them.
So the question is why? The White Audio amp with the ARC LS2 was silent. The White with the DS Jr directly feeding it was silent. Plug in the BHK Pre and I easily hear every tick up the volume dial, real loud POPS on start and shutdown and loud pops at 25 and 52. Swap the White out for the Pass amp and dead silence. No audible sounds when turning on or off the BHK, and only the most subtle tick at the 25, 52 markers.
Makes no sense to me. Would be interested in other’s theories.
In one paragraph you say the BHK pre and Pass are “Dead Silence” and then in the next paragraph you say the BHK pre and Pass amp make noises. Which is it?
I reread my post and don’t see the contradiction. Anyway, I was trying to say that swapping out the White for the Pass amp resulted is a totally quiet volume control. One could quickly point to the White amp as the culprit, but I point out the White with the ARC LS2 was dead silent too. It is only the White and the BHK Pre combo that resulted in very audible clicks with each turn of the dial.
Make no mistake, I’m very happy now with no audible clicks with the Pass-BHK Pre combo, but I’m still curious.
Glad you got the improvement you were looking for. Is the White amp single ended or even single ended with convenience XLR inputs. Reason I ask is that I have found that the BHK pre is not fond of SE amps and I have tried several.
It sounds like the Pass amp might have lower gain than your original White amp. Just speculating, but that’d be my guess.
The White amp has a 26.5 db gain while the Pass amp is 26 db, where the BHK 250 is 30.5 db. My guess is the difference in gain between the White and Pass amps is too small to be cause here. Also note that I’m using the identical interconnects and power chords (your AC5).
Understand I’m not reporting or complaining of a problem. I happily lived with the White/BHK-Pre combo with volume control ticks & pops. Now I’m ecstatic that they’re all gone with the Pass/BHK-Pre combo. But considering the topic of this thread and the number of people asking why the Pops, thought this was an interesting avenue to consider.
Indeed and, clearly, not the gain issue at fault. One guess would be CMR (common mode rejection). If one amp has better CMR than the other that could explain it. I assume with both amps you’re balanced?
Yes interconnects to both are Balanced and in fact the identical interconnects (Kimber Hero), just swapped from one amp to the other. I’ll have to google CMR and get educated. Is there a Paul’s Post on it? 
Cool RayK. I’ve been reading about the 250.8 lately. Dreaming about replacements for my Bryston 14BSST2 to pair with my BHK pre.
Please send your thoughts on this pairing once your amp settles in! Thanks. T