Question on my new BHK 250

That is the very obvious next question for which I have no answer.
I have no idea how to work out what dimension dampener corresponds to the tubes I’ve ordered. No idea who makes the most effective dampeners. Nada.
Guess I’ll head over to the dampeners thread :slight_smile:

I can see this becoming an obsession

Herbies tube dampers. You need the RX-9

Ordered :slight_smile:
Thanks!

Congrats, hope you can squeeze them in. I’ve got multiples of the Herbies and have used them on other gear including the BHK preamp but didn’t try them on the amp when I swapped the tubes before I even fired it up the first time.

@marcus46 - careful on ordering the Rx-9; slightly larger footprint than the SS-9. I believe it may not fit on your BHK250. Either dampener fits easy on the BHK Preamp. You might want to rethink the Rx-9. The Rx-9 & SS-9 are in route and should be here this week (Texas to Arizona; shipped yesterday). You might want to hold off ordering the Rx-9 till I show you (photo), if the Rx-9 fits the BHK250 amplifier. Robert Herbelin of Herbie’s Audio Lab is very understanding about changes in orders; might want to email him about pausing your order telling him Richard is verifying the Rx-9 or SS-9 fit in the BHK250 amplifier. Robert has never worked with the BHK250; therefore, he has no idea about how tight the BHK250 space is for tube dampener. Some on another thread said even the SS-9 did not fit, others said they fit, but very tight. So if there are any fit issues with the SS-9 on the BHK250, there will surely be issues with the Rx-9 fitting since the Rx-9 is slightly larger than the SS-9. I’ll start the installation with the BHK250 amplifier first; checking both the Rx-9 & SS-9 to see which one fits. In addition, I will remove the BHK250 amplifier from my rack and take pictures of the fit, giving you a definitive answer with photo proof.

Make sense?

Thanks for the heads up. I’ve just sent Herbies an email asking the to hold off on shipment until I hear back from you.

Regards
Mark

@markus46 - OK, sounds like a plan. I will follow up; should have them by next week tops, hopefully by this weekend.

Much appreciated. I just got a message from Robert saying he will hold off shipping my order until he hears back from me.

Crisis averted !

@markus46 - yes, reason I followed up with you so quickly. Robert is a great guy and doing business with him is really easy. I just got my Focal Utopia head phones and Questyle Qp2R player today. My BHK Preamp got delivered too; however, the Nordost Valhalla 2 (0.6m) XLR cables won’t arrive till next week. I ordered (2) sets of custom Nordost Heimdall 2 head phone cables (4m 1/4in jack & 2m 4pin fully balanced 2.5mm jack) that won’t be here till a few more weeks. So I am just listening to the QP2R w/ Utopia headphones with 3.5mm standard jack till custom jack comes in. All other head phones I have used are not even in the same zip code. I can’t wait to listen to my BHK preamp with these head phones.

@markus46 - Just got the mail tracking for the shipment. Should be in by TUES next week. So, by WED/THU I should send you an update with pics.

Awesome! Thanks

@Markus46 - Adding New BHK “Select” PCC88 tubes w/ tube dampeners to PSA BHK250 Amplifier - These pictures will show the process, giving evidence as to the fit not just the statement: “they fit”. The Rx-9 tube dampeners would have been really tight and rubbed against either the inside of the tube door or the metal wall beyond the tubes. Since there would have been contact with external environment (wall & or door), the SS-9 are your safest bet with zero touching.

12/18/18; 1100 - I now have ~12hrs on the tubes and they sound better than the stock tubes. At 12hrs a day, 30 days a month, 7 months ~ 2500hrs stock tube play.




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Absolutely fantastic! Thanks for your effort in documenting your results.
I will change my order to the SS-9’s toot sweet :slight_smile:

BTW. My Mullards arrived from Germany and they have tamed the ‘hot’ edge in the treble. I’ll give the Tungsrams a shot when they arrive.

Cheers
Mark

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BHK “select” tube w/ Rx-9 dampeners for BHK Preamp -
I just changed the PSA BHK Preamp stock tubes for the BHK “select” tubes. I modeled the shelf space with VISIO before I ordered the Herbies Fat Dots (0.250in). They’re exactly as specified; wanted to maintain 0.25in space on top & bottom of preamp for airflow and also isolation from shelf & PSA DS DAC. Didn’t like the (4) large felt dots on the bottom of the PSA DS DAC (stock) for airflow if I stacked the units so I decided to get rid of the 3/8in feet and replace them with 0.250in Fat Dots (0.25in) and they stacked as planned.

The down side is I have to wait for my Nordost Valhalla 2 XLR cables (drop shipped) to listen to my new BHK Preamp. I have a set going from the PSA DS DAC to BHK250 amplifier; love them! Oh well, looks like I will have to listen to the new tubes in the BHK250 amplifier.

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So after setting up the PSA DS DAC on top of the PSA BHK Preamp with just 0.250in on top of the BHK Preamp, I turned it on for 4hrs (thermal soak) to see how the BHK Preamp was heating up the PSA DS DAC. Come to find out it was getting pretty toasty… :slight_smile: I reconfigured the rack to allow the BHK Preamp room to breath and not all over the bottom of the PSA DS DAC.

Also, love the BHK Preamp tube “ON” time counter - down side is that I can’t use it for the BHK250 AMP because there will be times I just listen to the head phones and my AMP will not be turned on. I guess I will have to get a sense of the speaker/headphone listening ratio…

Much Better Configuration -


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Glad to see you changed your layout. When I saw the shot with the DAC on top of the preamp I immediately thought that would have a negative effect on the lifespan of the preamp. it has allot of vents in the top for a reason.

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@sixpack1 - Yeah, wishful thinking. Being an engineer, I measured the 1m AC-12 power cords already; have to have a back up plan. That was the first thing Brett commented on 4 hrs ago in a private IM… “have you lost your thermal mind”, in a nice Brett sort of way… :slight_smile:

Bonus - rolling tubes is really easy in this configuration.

Also, as an aside, the new BHK “select” tubes sound better right away. Not amazing, just a little warmer, better background. They need to be broken in…

Yeah, just after 30min in the new configuration both Preamp & DAC cooled down quite a bite. They are now quite cool to the touch. Experiment confirmed not to place a component on top of Preamp without sufficient space. 0.250in is certainly not the distance…:+1:

Those glass shelves can support all that weight? The P-20 and the BHK-250 are both extremely heavy. I would hate to hear a loud crash in the middle of the night and for you to come down and find the P-20 on the floor with the 250 on top of it!

@sixpack1 - I believe they will hold over 200lbs each and are quite thick. The rack has been in operation since May, 2018 with zero fatigue. You would be surprised how thick the glass is…

cardi,
Wow I did not know any glass could hold that much weight. I am sure it will last well for you than.