Bob Carver LLC Black Beauty Review

Dracula1 I read your post about upgrading the Black Beautys by simply swapping out the coupling caps. I can't read a schematic, is there an easy way to figure out which ones they are? I can solder pretty well and wish to try this.
How difficult is it to swat out the volume controls?
Kent

Dragon & Kenster

Dragon give Walt at Underwood Hi-Fi a call 770 667-5633 for an answer.

Kenster FYI, you may have read my post on the other Bob Carver thread above. Any modification other than tubes may void the products seven year transferable warrantee. That said, Dracule gives a good description of the cap replacement on the second page of the other thread.

Dragon, personally I think the sweet spot is with the Cherry 180, if you don't need the extra power. I'v heard both amps, but not in direct comparison. I was told the Black Beauty might be a little more sweet sounding, but that may be due to the KT120s. According to the man himself, there shouldn't be a noticeable difference in sound quality between the two, except for the extra headroom the BB provides.

Kenster, I'm not a blood sucker (DraculA)...I think you have me confused with my ex.

If you open up the one mono block chassis, you should see two 0.22 uF caps, one for each bank of push pull output tubes. Those are the coupling caps you need to replace. Bear in mind, each mono block also has one 2.2 uF feedback cap. Leave that alone, because only a few percent of the signal actually go through that cap. I don't know what the caps look like because my amps are not the current production version. They may have switched to a different brand, but I can tell you they will be small, not big like most audiophile caps. If you shoot me a photo of the inside of your amp, I can locate them for you.

The volume control is easy to replace, if you know how to solder. It goes right before the input (grid) resistor to the 12AX7 tube.

Oh yea, I've been meaning to replace the input resistor as well. As far as resistors go, this resistor probably has the most influence in the sound. It needs to be 3.3 kOhm, 0.5 watt resistor with 300 V rating. May be a Shinkoh metal film, nude Z-foil, Riken carbon film, etc... depending on your taste.