BHK preamp - volume pops

Has anyone figured out why the BHK preamp ‘pops’ at specific volume levels?
When i turn the volume up to 53 on the indicator, the sound pops, or clicks. pretty darn annoying.
I have the volume set at 100 on the Direct Stream DAC.
Any insight greatly appreciated.
Cheers! TJ

I’ve never gotten any wear near 53 so don’t know about that one, but the one at 25 is very similar to what happens with the W4S STP-SE at two specific spots and the volume controls are very similar in execution.

And I attempted to answer it based on ownership experience but as usual Brodric decided to use your question as another attempt to further his “defective PSA gear agenda.” The two attenuated volume control noises on the STP-SE happen at much lower levels, 8 and 24, so not as noticeable through the speaker but they are there. To that add the higher gain level of the BHK and the noise would be more audible. I have seen the technical explanation from EJ in the past as to why it happens at specific locations but don’t remember where.

@tj-sully - If you will notice, it does it at 23 too. I believe this has to do with gain ranges on the BHK PRE. There have been posts written on the subject. I like to keep my BHK PRE @ 65 for streaming and 70 for DMP and adjust my DSD accordingly…

Specificity for ADD

Hope this helps…

I find the popping varies between tubes. Any 6922 variant in my pre’ tends to be quite loud during the volume changes. I think it might also be louder for tubes that are going bad. 12AU7 tubes have less gain and tend to be a lot quieter during volume changes though I have on occasion found some 12AU7 variants that are louder.

My it all the time clicks. I have changed pipes several times without it helping in any way.

“The BHK Signature’s volume control was not, however, completely silent. At two points on the volume scale—between “23” and “24” and between “52” and “53”—I heard a moderate click from inside the preamp, similar to the sound it makes when a new source is selected. Furthermore, each 0.5dB step was sometimes accompanied by a soft, short chiff from my speakers. This chiffing varied in volume throughout the listening period: it was noticeable at first, then faded to inaudibility, then returned, then faded again. As I write this, it’s just barely audible at a few spots in the volume range with no music playing. I’m thinking this must be one of those tube frailties Paul McGowan objects to (footnote 2).”
Read more at https://www.stereophile.com/content/ps-audio-bhk-signature-preamplifier#m60GhsSbF6gf4zY4.99

I screw it up to 53 and then I use my DS as volume control

The popping and clicks, supposedly the worst at about 25 and 52, are due to the unique design of the volume control. Part of the volume adjustment is through altering the gain of the tube which is claimed to improve SQ over traditional techniques. Since the gain change only works over a certain range, at certain points a “step” occurs and the gain change range begins anew -apparently at about 25 and 52.

Some of those who also use the DS Dac, find a “fixed” setting of the preamp that sounds best with a range of settings on the DACs lossless volume control and thus avoid the clicks. Some also believe this to be the best SQ overall.

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Thanks for the explanations and suggestions kind folks. I will experiment to find a sweet spot on the BHK volume setting and use the Direct Stream for the main volume control. Love the products, company philosophy and innovative designs, so I suppose a few minor inconveniences are worth it!

@tj-sully - If I were you, I’d read through the entire post (link I provided) to get a good understanding of what is being conveyed as to using the BHKPRE in it’s sweet spot and the DSD as volume control. There is a lot of great information in the whole post. Also, the BHK PRE will have a different “sweet spot” for every source (input). I have only two (Matrix {streaming} & DMP) so my choice is 65 for Matrix and 70 for DMP. Your settings may change and it is really easy to understand it as you listen.

There is even a conversation about how counter-intuitive the whole BHKPRE used this way is to setting up a noise floor in the audio chain. Has to do with how the DSD volume setting is implemented and Ted even weighs in… really good read…

Anyway - good luck… happy listening

I find the little plops with volume changes amusing given they are a result of the design. The BHK volume control is also interesting in that it is a variable amplifier gain stage instead of an attenuator. I similarly enjoy the feel and little noises of a discrete resistor ladder volume control, as well as the concept.

Once one knows there is nothing wrong, just enjoy the characteristics of the unit.

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At 53 there’s an internal relay that switches in an attenuator. The volume control is quite complex in operation, simple in theory. Basically, there’s an input attenuator consisting of just two resistors that are switched in and out (one at 53 and I don’t remember
the other number). This is the major step attenuator. Between those major steps the volume control increments the volume in 1/2dB steps by changing the gain of the vacuum tube stage (our Gain Cell approach).

While this isn’t the most elegant of solutions it is most certainly the best sounding volume control we’ve ever managed to pull off.

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It’s not a problem. It’s part of the design as Elk describes. The design is unique which is what might happen when you don’t follow anybody else and you create and innovate. This is one of the best preamps that you can buy because BHK thought about the volume control in an innovative way.
I’d say that if that poof is unbearable, avoid going back and forth between 24/25 and 52/53.

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So which volume control are most using, the DSD’s or the BHK pre? Is it better to set one and use the other? I’m most concerned about SQ.

@Gary_M - I placed a link “life at 80 to 90…” above, a great read to help with your question. I prefer using the DSD to adjust the overall system volume, understanding the “sweet spot” (volume) for the BHKPRE with each source. This gives me the best overall SQ and bonus: I don’t have to be annoyed at 25 & 52 with the BHKPRE cause I’m above those two values.

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Reading that thread gave me a headache. Dirk had mentioned to me once before that lowering the Dac volume to 72 improved the sound of his system tremendously. So I’m wondering where is the improvement coming from? Is it the Dac that sounds better at 72, or is it the fact that the preamp now needs to be turned up, or is it both?
I’ll be getting my BHK preamp next week, so I’ll be torturing myself trying to determine the sweet spot of each components volume control. Probably wait until the preamp is fully broken in first though.

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Best advice for me is not to over think this detail. BHK preamp is great at all volume settings. I’ve got my DS DAC set to fixed volume 100. That way after a power cycle I’m right back at full volume from the DAC.

I too have noticed an occasional low level click when slewing the volume of my BHK pre. I take the view that unless it poses some risk to the tweeters in my loudspeakers (it’s nowhere near that intense), it is simply a characteristic of the hybrid volume control approach that Bascom settled on. Which is as close to transparent in operation as any approach in a linestage preamp I’ve ever owned. Once you’ve set your volume control to where you want it, relax and enjoy all the sonic bliss the BHK pre delivers.

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Each 0.5dB step accompanied by a soft, short chiff from my speakers.
:angry::angry::angry:
I hate any of these clicks in my speaker and they reduce the total enjoyment of my equipment. Therefore, I use DS as volume control.

I usually do not buy a volume control that clicks each time you turn up and down. Foolishly …Perfect spirit weakness

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@michael-denmark - More love from America…:partying_face::scream::crazy_face::heart_eyes::smiling_face_with_three_hearts::kissing_heart:

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more clicks from the USA…:scream::smile::loud_sound::loudspeaker::peace_symbol:

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