[Nic Rhodes]

Is your base stained or a new wood? Just done some in Wenge and Black Walnut to try but am not sure how to finish them atm.

 

[MattTCG]

  Get a 12BH7, so long as you're getting Speedball. It's super quiet and they are actually still reasonably priced

 
 

   
Great pic.. I dig the dark base.. and the glow of the 5998 is so damn sexy.
 
What Brunk said.. 12BH7's are renowned for having no microphonics... a great choice to have (at least one) if you've got the speedball installed.
 
I've made recco's on the 650 thread as far as input tubes go.. if you're going to be using the 650 w/ the Crack (and a 5998 for the output tube), I think an RCA "black plate" 12AU7 (or the "clear top") is a must hear combo.. stunning sound.  The Mazda CIFTE 12AU7 was bad ass with the 650, too.. great for electronica/hip hop/rock.

 
Thanks guys!! Could you provide some recommended sources?
 
How about this:
 
http://www.ebay.com/itm/RCA-12AU7-ECC82-VACUUM-TUBE-1956-BLACK-PLATE-D-FOIL-GTR-SINGLE-RARE-SWEET-223-/221330280792?pt=Vintage_Electronics_R2&hash=item3388501158

 

[skeptic]

Off the cuff, I prefer my 1950's tung sol 12bh7 to the rca's I've heard.  For that matter, old stock tung sol 12au7's also sound great and can be had quite cheap on ebay.
 
I would describe both the 12au7 and 12bh7 tung sols as very clean, neutral tubes.  By comparison, my amperex bugle boy 12au7 and 1950's rca 12bh7 are a little warmer/less extended by comparison.  Alternatively, I hear my rca clear top and mullard shield logo 12au7's as having slightly brighter trebles than the tung sols.  I don't particularly care for my 1960's rca grey plate 12bh7 but have trouble putting my finger on exactly what it is about the sound that I find less appealing than most of the others.  
 
At the end of the day, my best advice is to buy a handful of cheap tubes on ebay and see what you like.  Tubes that read "strong" as opposed to nos are just fine.  These things are good for thousands of hours of use.

 

[bdr529]

I am using a Tungsol 12BH7A that is rebranded as "Regency" in mine right now.

To be honest I have a real hard time hearing a difference switching the drive tubes, but this one looks the best so far haha . It is the one in the picture I posted last night.. Anyway all three drive tubes that I have sound good and are equally quiet. The other two I have are RCA 12BH7A long black plate and a GE 12AU7A.

 

[Doc B.]

RE the "there is a tiny bit of hum when I turn the amp up far louder than I would set it to listen to music" -

The Speedball upgrade increases the gain of the circuit and thus the noise floor will be amplified a bit more. Thus it may just hit the threshold of hearing if you turn the volume up far louder than you should for listening.

 

[ben_r_]

RE the "there is a tiny bit of hum when I turn the amp up far louder than I would set it to listen to music" -

The Speedball upgrade increases the gain of the circuit and thus the noise floor will be amplified a bit more. Thus it may just hit the threshold of hearing if you turn the volume up far louder than you should for listening.

Got it and that makes complete sense. It's kinda what I was assuming but I was just curious if everyone else experienced the same thing. Then when my friends made a distinct hum sound and mine made a more normal shhhhhh noise sound I was thrown off since they were two very different sounding noises.

 

[Solarium]

I know the consensus that BTH crack is amazing with the HD650, which I currently have. I plan to eventually upgrade to HD800 and the HE-500 sometimes down the road, how does the BTH crack handle those HP's?

 

[MattTCG]

^^ Won't work at all. Bottlehead sells other amps for planar magnetic hp's. 

 

[olegausany]

But great for HD800

 

[skeptic]

  But great for HD800

 
x2.  To my ears, it's one of the best budget hd800 amps out there in fact.  
 
If you're looking for an absolute end game setup for hd800's (and that will also handle orthos), mainline is what you want.  It is phenomenal - except for the part where I can't tare myself away from listening at night and wind up sleep deprived and/or with wife aggro.  All in all, a nice problem to have.

 

[olegausany]

   
x2.  To my ears, it's one of the best budget hd800 amps out there in fact.  
 
If you're looking for an absolute end game setup for hd800's (and that will also handle orthos), mainline is what you want.  It is phenomenal - except for the part where I can't tare myself away from listening at night and wind up sleep deprived and/or with wife aggro.  All in all, a nice problem to have.

HD800 are my end game headphones and I have no interest in orthos for my desktop setup and S.E.X. handles HD800 for me from speakers taps but I still would be interested to hear mainline.

 

[MattTCG]

Despite my love of planar magnetic hp's, the hd650 with crack could be my end game. 

 

[rtwilner]

I have to admit not reading all 3500 posts in this thread...
 
Like many, I would be using this amp close to my computer.  Are there any issues with interference from lack of shielding ("gravity mounted" wooden chassis)?

 

[MattTCG]

None that I have heard of. 

 

[gikigill]

Nope, mine sits next to a solid state amp and the computer without any problems.