[cfcubed]

No, use the base part & classes specified (e.g. BC550 - class C).  E.g. in the case you ask about either BC550CTA (ammo/tape) or BC550CBU (bulk/loose).
 
Curious, how many builds do you have under your belt?   The CTH is an intermediate level build, *lots* of parts in a tiny space, and misplacement / misalignment of any can ruin your day.  IOW IMO would not recommend CTH as a first project.

 

[Pilou]

I only have two builds has my belt: a Cmoy and a O2 amp!
However this is not the construction that worried me but right choice of components

.

 

[cfcubed]

Sorry I did not mean to offend, sounds good - an O2 build is a good warm-up
 
Good to confirm any questionable sub parts as you are doing.  But concentrate on Description field value in CTH XLS BoM when an exact part # is not available from your source(s).  E.g. in the Digikey BC550CGOS-ND EOL case see they suggest BC547C as direct substitute but would first search for sub using "BC550C" (from Description).

 

[hpamdr]

I'm enjoying a lot my CTH and got a box of russian tubes with inside some submini tube (6N16B-V). I've seen than on the proto board, you started with it !
Does this tube can still be used  with Rev A design?
Do you have an optimal socket conversion cabling ?   (from filament to noval skipping pin 9)

 

[cfcubed]

Had to go back in my archives for this one
 
First off I suppose your CTH has a regular 9-pin socket installed....  So maybe use a "9 PIN TUBE SOCKET SAVER FOR 12AX7" or "9 pin Machine made tube socket 12AX7" (w/o center pin) from fleabay to wire the pencil tube into so it can be inserted in CTH 9-pin socket.
 
Attaching my chicken-scratch sheets from when used 6N16B (6.3v heater) in the proto, to help you map its pinout.  Yes leave pin 9 unconnected.
 

 

 
N.B.  Of course use something like small dia. heat shrink tubing on 6N16B leads if there's any chance of them shorting.  If you do this please post back your results/impressions.

 

[hpamdr]

Thanks this is quite helpful !
I will do it when i will receive some socket saver and try to do an adapter.
 
For now i also got some russian 6N6P (6н6п) i like the "airy" sound even if at first it seems to be not very fast. The gain is not very high but all is ok to power HD650 and T1.
The tube after 30 minutes of (active) burning  is more dynamic and i like a lot the sound of the CTH with it specially for pop, small ensemble.

 

[rds]

Bumping this thread to say thanks to Dr. Cavalli, cfcubed, and everyone else involved in creating this great little buffered tube amp. It's travelled with me to three different cities and is a fond reminder of my head-fi diy days. Here it sits on my night-table in Switerland, far from my hometown of Vancouver - more than 6 years after I originally built it.

 

[cfcubed]

Thanks for the post rds, good to hear your CTH is still serving you well.  Though I listen mostly to speakers these days, I do rotate a CTH in every now & then when using cans & still enjoy it.

 

[emilio84]

Just finished reading this and pretty much any other CTH thread I could find. I'd very much like to build one of these amps. Tossed the BOM into Mouser's BOM tool and while there are approx 13-15 components that have been end of life'd it seems there are comparable current products available. The biggest unknown is obviously the PCB and after some digging I found and ordered one from what now appears to be an abandoned site (joeaudiophile) as after almost a week I haven't received any sort of shipping notification even though the order was processed. Emails to the site haven't been responded to either unfortunately.

Is there any chance anyone has a spare pcb or kit kicking around? I'd even go as far as having a pcb (or batch) made if someone would be willing to supply me with the gerber file.

The design seems so well received that it would be a shame to have it disappear into the archives.

 

[Misterrogers]

Hey!
 
Apologies - Not sure what's going on communication wise. I sent you an email a couple of days ago asking for your shipping address. Also, just checked my junk folder; nothing in there from you (or anyone) unanswered. Anyway, glad yo posted here. Please verify you're emailing to mike@joeaudiophile.com. Or, you can provide your shipping address via message hear at Head-Fi. As soon as I get a shipping address I'll send one off.

 

[emilio84]

Hey!

Apologies - Not sure what's going on communication wise. I sent you an email a couple of days ago asking for your shipping address. Also, just checked my junk folder; nothing in there from you (or anyone) unanswered. Anyway, glad yo posted here. Please verify you're emailing to mike@joeaudiophile.com. Or, you can provide your shipping address via message hear at Head-Fi. As soon as I get a shipping address I'll send one off.

Guess who just found your email in HIS junk folder.... Yeah... It's me. Anyway, for those of you following along at home, Mike did reach out to me and all is well. Really excited to get my build going!

 

[wolfield]

Does anybody have the schematics still laying around? Would someone be kind enough to share?

 

[javaboju]

I might still have these somewhere on a computer.
Let me do some digging.

 

[wolfield]

I might still have these somewhere on a computer.
Let me do some digging.

Have you found anything at all?

 

[proid]

Does anyone have the schematic for CTH? I can no longer find it.