[jhljhl]

   
I haven't listened to the BL63 in a long time. However, it was manufactured by GEC, and as best as I can remember, it has that characteristic GEC sound, airy and detailed, with very good bass.
 
And I seriously doubt it would be safe to use in the WA5. The BL63 heaters draw about 1.2 Amps, about twice the current of a 6SN7. So I would not suggest you try it without checking with Woo first. However, in a Glenn OTL it is perfectly fine.

I think the WA22 can use the bl63 since it can handle the ecc31 which uses 1 amp?

 

[gibosi]

 
I think the WA22 can use the bl63 since it can handle the ecc31 which uses 1 amp?

 
I would still recommend that you contact Woo. The ECC31/ECC32 is rated at 0.95 amps and it appears that many headphone amps using the 6SN7 as a driver can safely handle it. Designers typically expect that users will want to use the ECC32. But 1.0 amps may well be the maximum safe heater current. The BL63 is not widely known and most designers would not expect that their users would want to roll this tube. I might speculate that many designers don't even know this tube exists. Further, checking the BL63 specificiations more closely, it is actually rated at 1.27 or 1.3 amps. So again, I would not encourage anyone to use this tube without checking with the manufacturer first.

 

[jhljhl]

   
I would still recommend that you contact Woo. The ECC31/ECC32 is rated at 0.95 amps and it appears that many headphone amps using the 6SN7 as a driver can safely handle it. Designers typically expect that users will want to use the ECC32. But 1.0 amps may well be the maximum safe heater current. The BL63 is not widely known and most designers would not expect that their users would want to roll this tube. I might speculate that many designers don't even know this tube exists. Further, checking the BL63 specificiations more closely, it is actually rated at 1.27 or 1.3 amps. So again, I would not encourage anyone to use this tube without checking with the manufacturer first.

Agreed emailing Woo would be wise.

 

[MIKELAP]

 

   
I would still recommend that you contact Woo. The ECC31/ECC32 is rated at 0.95 amps and it appears that many headphone amps using the 6SN7 as a driver can safely handle it. Designers typically expect that users will want to use the ECC32. But 1.0 amps may well be the maximum safe heater current. The BL63 is not widely known and most designers would not expect that their users would want to roll this tube. I might speculate that many designers don't even know this tube exists. Further, checking the BL63 specificiations more closely, it is actually rated at 1.27 or 1.3 amps. So again, I would not encourage anyone to use this tube without checking with the manufacturer first.

Agreed emailing Woo would be wise.

 

[Xcalibur255]

  Just curious, Which 3 do you have ?

 
Glenn made 45 DHT, Glenn made OTL, Dragon Inspire IHA-1.  I greatly enjoy all 3, I can't see myself splitting time among even more amps, so no more buying for me.  Which is a shame because there are designs out there I'd really love to try.

 

[Xcalibur255]

 

That's pretty interesting information.  The Woo amps used to be limited to 3A on rectifiers for sure, I wonder when they changed their power transformers to allow for more overhead.  That opens them up to some uncommon tubes like the 5AW4 and 5AU4 that we've been using here with Glenn OTLs.  I'm guessing they went up to 1A on the drivers to accommodate the ECC32.

 

[magiccabbage]

 
 I'm guessing they went up to 1A on the drivers to accommodate the ECC32.

Wonder if I can use that tube on my WA5?

 

[3083joe]

Wonder if I can use that tube on my WA5?

The ecc32, yes

 

[gibosi]

Sorry for the crappy picture...  Four early 1950's Sylvania flat-plate 6BL7's, two per side. Sounds great, but then doesn't everything sound great in Glenn?
 
Will let them cook for awhile and then swap out the rectifier and driver with tubes I like better....
 
 

 

[JoelT]

  Sorry for the crappy picture...  Four early 1950's Sylvania flat-plate 6BL7's, two per side. Sounds great, but then doesn't everything sound great in Glenn?

Pretty cool. Looking forward to your impressions. What are the dimensions of the adapters? Just curious as my output tubes are offset towards the back of the unit.

 

[2359glenn]

  Sorry for the crappy picture...  Four early 1950's Sylvania flat-plate 6BL7's, two per side. Sounds great, but then doesn't everything sound great in Glenn?
 
Will let them cook for awhile and then swap out the rectifier and driver with tubes I like better....
 
 

I like the flat plate Sylvania the best of all 6BL7s.
Does 2 of them sound better then 6AS7s??
I know that 3 of them in amps I made to take them sound better then any 6AS7 including the GEC.

 

[2359glenn]

Try 6BX7s too for a different flavor of sound

 

[Xcalibur255]

  Try 6BX7s too for a different flavor of sound

 
Seconded. 

 

[2359glenn]

 

  Try 6BX7s too for a different flavor of sound

 
Seconded. 

Tyrell can you try this adapter in the small chassis?
One 6BL7 isn't enough power really in this amp.

 

[whirlwind]

  Sorry for the crappy picture...  Four early 1950's Sylvania flat-plate 6BL7's, two per side. Sounds great, but then doesn't everything sound great in Glenn?
 
Will let them cook for awhile and then swap out the rectifier and driver with tubes I like better....
 
 

Very nice, Ken