BHK Signature 250 or 300 Tube Rolling

Welcome, vvolant! And thank you for the report.

+1. Greatly appreciate the input and look forward to further reports.

Just thought I’d chime in with some tube swapping experience. I changed my input tubes on the 300 mono’s 3 weeks ago to some Amperex 6922 USN-CEP PQ White Label Gold Pins and I just love, love, love their match! I tried the amps first with the supplied Genelex “Gold Lion” E88CC’s and found them OK. I replaced these with the Tungsram PCC88’s from Upscale that everyone was liking, and they definitely improved upon the stock tubes, losing some of a thickening in the upper bass, lower midrange that I was hearing, while also having a firmer grip in the bass and more tactile harmonic development down there. I felt I was hearing more clearly into the music and getting better bass.

The Amperex 6922’s lose none of that, but add a greater sense of transparency and also a touch of midrange articulation and deeper harmonic development - - a magic act, in my book! It is so hard to get that kind of balance, and in my system, this is doing it, FWIW.

When I liked the Siemens ECC88 and BHK recommended the Tungstram PCC88, and after trying the Tungstram and still preferring the Siemens, only one conclusion could be drawn: there was something wrong with my system. I was running a P-5 to power the DirectStream DAC, feeding the Signature 300s. I knew the Magnapan 20.1, using Mye stands, are set up properly. I am using Cardas Clear interconnects and speaker cables.

I added a P-10 for each monoblock, SR Black fuses for the DAC and amps, a LANRover USB Transporter, Nordost TC Sort Kones under the stacked P-10s and 300s, Kimber power cords, and upgraded the DAC software to Huron. I even added Herbie’s Hush Puckies for the speakers and UltraSonic Rx dampers for the tubes.

The only remaining variable is my hearing, which I cannot fix. The Siemens ECC88 sound better to me. The midrange is not as rich, but it is clearer. The lyrics of songs are more easily understood. The bass is cleaner and fuller. The high end sparkles. I am going to try the Siemens E88CC next. With all due respect to the designer of the Signature 300s, one of the best amps on the market, my only conclusion now is that this is a preference, with no correct answer.

I am not an addict. I can stop at anytime. I would not use tube rolling as an excuse to buy more gear in my search for perfection.

vvolant said
  • Voskhod 6n23p NOs from the 60’s (around 15 euros for the pair)
Want to share where you found these?

I just changed the speakers. I will roll the tubes again.

Rob said
vvolant said - Voskhod 6n23p NOs from the 60's (around 15 euros for the pair)
Want to share where you found these?
I found those on Ebay.

Today I received and immediately tried a pair of amperex 6922 PQ gold pins white label (85 euros). They sound very very good

To me the sound is very similar to the one produced with the voskhod. Perhaps they are slightly more delicate but I am not sure I could differenciate them in a blind test.

So the voskhod are still the winner if we look at the performance/price ratio.

Wow! That’s good news! I will have to try some of the Voskhod tubes. Thanks for the heads up on your comparison.

Not quite 2 weeks into ownership of the new BHK preamp I finally decided to audition the headphone section against my reference, a dedicated headphone amp (solid-state with adjustable gain) that has been the mainstay of my HD800 listening for the past several years. To my dismay, the BHK did not come close.

Then I swapped the 12AU7 Psvanes that PS Audio ships with the BHK for a pair of Upscale Audio’s “BHK Select” Tungsram PCC88/7DJ8s (the ones with the Bundespost markings). Frankly, I was astonished by the degree of improvement. The new preamp now sounds at least non-inferior to the reference headphone amp – something that has quite surprised me since nothing else has been able to do that to date.

Obvious question: What headphone amp is your reference?

Bakoon HPA-21, using its current-mode output jack.

vvolant said Voskhod 6n23p NOs from the 60's (around 15 euros for the pair)
Can you share your seller via PM to those that request it? There's a number of sellers of these tubes on EBay... this is an area where there might be some shady ones, I'd prefer to deal with someone you've had good luck with.

I suspect it is not appropriate to list the seller in this thread… why I’m suggesting only via PM.

Sending a PM right now.

THANKS!

Greg in Mississippi

vvolant, please PM me, too, if you want to share which eBay seller you got those Voskhods from.

pm sent

Gregory A Stewart said I suspect it is not appropriate to list the seller in this thread
I do not see any problem publically identifying a seller with whom you have had a good experience. In fact, it appears to be a kind thing to do - for both potential buyers and the seller.

I updated to red cloud and added a Cardas Clear network cable. The Siemens ECC88 sound better to me. It has better resolution than the Tungstram.

It is too bad that reviewers are not listening to the BHK Signature 300s with either Siemens or Tungstram tubes. It is a significantly better amp with these tubes.

We often do not have the collection of tubes to try different combinations. Plus there is only so much time to conduct the review. Thus we generally conduct the review with the device as it is shipped.

Eric

HiFi+ Magazine

Also, not everyone wants to spend time and money on tube rolling. I think it’s entirely fair to review the component as delivered by the manufacturer. Presumably the company is satisfied with the product as shipped (they shouldn’t be shipping it otherwise). If a reviewer has tubes and the time to try them, that’s a nice extra tidbit.