[Rossliew]

BHSE is self-bias and the power tubes on it should last a long time.  I remember Birgir  mentioned that the good old Mullard tube should last for over 10,000 hours.  Yes, I deeply miss my BHSE but I do have the T2 so I am not missing out on anything but the aesthetic of the amp.

Thanks for the clarification..a few of my friends have advised me to just go for the T2 instead of a BHSE - is this a justified call?

It's not manual bias...you're only adjusting the balance of each push/pull pair, and the DC offset in each channel. And I've now tried 2 quads of 1960s Holland plus 1 quad of 1970s Mullard; all 3 are very very close to each other in adjustment settings. After PLENTY of warmup, all 4 measurements end up close enough to 0 (i.e. close enough to not matter), that I can actually roll these quads and not need to readjust. I definitely wouldn't recommend rolling an unknown quad without checking, though. And rolling daily isn't a great idea either (stress on sockets, tube pins/base, and boards).

Apparently the BHSE runs EL34 well under their power ratings, so a good tube should last a long while.

I see...i stand corrected then. Have checked out Justin's video on checking the bias..looks pretty straightforward but an extra step nonetheless when swapping tubes. Is the stock tube set really meh sounding?

 

[wuwhere]

Thanks for the clarification..a few of my friends have advised me to just go for the T2 instead of a BHSE - is this a justified call?
I see...i stand corrected then. Have checked out Justin's video on checking the bias..looks pretty straightforward but an extra step nonetheless when swapping tubes. Is the stock tube set really meh sounding?

 
The problem is most manufacturers will only install commercially available tubes, ones they can buy today. Nos are not commercially available.

 

[mulveling]

Thanks for the clarification..a few of my friends have advised me to just go for the T2 instead of a BHSE - is this a justified call?
I see...i stand corrected then. Have checked out Justin's video on checking the bias..looks pretty straightforward but an extra step nonetheless when swapping tubes. Is the stock tube set really meh sounding?

If you can snag a nice DIY T2 then go for it, and never look back. As amazing as the BHSE is, nobody will dispute the DIY T2's superiority.
 
I haven't tried any new-production tubes in the BHSE (if I didn't make that clear before). I tried 4 kinds of the Russian variants (3 New-Sensor types, plus the Winged-C) when tube rolling a couple of speaker amps years ago -- and based on that experience, I have absolutely no desire to try new-production tubes in my BHSE.

 

[litleGrasshoper]

To heard schubert ave maria which headphone is better 007,009,omega, or a he90?

 

[Rossliew]

If you can snag a nice DIY T2 then go for it, and never look back. As amazing as the BHSE is, nobody will dispute the DIY T2's superiority.

I haven't tried any new-production tubes in the BHSE (if I didn't make that clear before). I tried 4 kinds of the Russian variants (3 New-Sensor types, plus the Winged-C) when tube rolling a couple of speaker amps years ago -- and based on that experience, I have absolutely no desire to try new-production tubes in my BHSE.

Hardly anyone will build it and I suppose for a tropical climate like Malaysia, it can get too hot? Think I shall start with a BHSE first then move from there..thanks for the advice !

 

[JimL11]

  Power tubes don't last very long. 

Actually that depends entirely on how they are run.  Most tube power amps run them relatively hard, say at 80% of maximum, so they may last 2000 hours, perhaps less..  In the BHSE they are run at about 10 watts, which is only 40% of the rated 25 watts max, so they will last a long, long time, likely 10,000 hr for NOS tubes.
 
The BH is somewhat unusual in that the tube operating conditions are set by the current loads on the output plates.  The same is true of my SRX Plus design.  The bias sets the plates to zero volts with respect to ground.  This is different from most tube power amps where the bias control sets the standing current through the tubes.

 

[wuwhere]

So I just got my SRM-717 and with 007 Mk1, it sounds pretty good. My HE-6 on tube speaker amp kicks better in the bass.

 

[purk]

  So I just got my SRM-717 and with 007 Mk1, it sounds pretty good. My HE-6 on tube speaker amp kicks better in the bass.

It can get a good bit better actually with the KGSSHV.

 

[wuwhere]

  It can get a good bit better actually with the KGSSHV.

 
It has delicacy and smoothness. A little dark in a positive way.

 

[wuwhere]

I can understand now why some people still prefer planars. I'm still keeping my HE-6. With the Audio Research tube speaker amp, its great with piano. But the Stax is nice. Like Purk said, maybe all I need now is just a regular KGSSHV.

 

[purk]

  I can understand now why some people still prefer planars. I'm still keeping my HE-6. With the Audio Research tube speaker amp, its great with piano. But the Stax is nice. Like Purk said, maybe all I need now is just a regular KGSSHV.

Yes, you will need something better to wake the SR-007 up.  You can get by with SR009+SRM-717 to a degree but the SR007 needs something much more powerful.  The 717 is relatively dark amplifier and a little soft around edge making it not an ideal pairing  with the SR007...try 500V  KGSSHV or even a  KGST.

 

[wuwhere]

  Yes, you will need something better to wake the SR-007 up.  You can get by with SR009+SRM-717 to a degree but the SR007 needs something much more powerful.  The 717 is relatively dark amplifier and a little soft around edge making it not an ideal pairing  with the SR007...try 500V  KGSSHV or even a  KGST.

 
That's what I'm thinking as well, amps make a big difference.

 

[jibzilla]

  Yes, you will need something better to wake the SR-007 up.  You can get by with SR009+SRM-717 to a degree but the SR007 needs something much more powerful.  The 717 is relatively dark amplifier and a little soft around edge making it not an ideal pairing  with the SR007...try 500V  KGSSHV or even a  KGST.

 
As a previous owner of a 727ii and current owner of a 500v mjolnir full size I have to agree. The 727ii was a better match with the sr-009's and the kgsshv with the 007's imo.

 

[Jones Bob]

The BH is somewhat unusual in that the tube operating conditions are set by the current loads on the output plates.  The same is true of my SRX Plus design.  The bias sets the plates to zero volts with respect to *signal* ground.

FIFY

 

[JimL11]

Good point.  I need to make a small correction - according to an old KG post, the BHSE runs the EL34 at 18 mA and 400 volts, which means it dissipates 7.2 watts rather than 10.  That is less than 30% of max dissipation, so tube life should be very, very good indeed.