[sachu]

I think its nearing that time where i need to build myself one of these fancy CTHs

 

[cfcubed]

Erik -  I guess I'll change my sig... Those Beyers work w/CTH & proper tube choice makes them sound OK, but I like my other combos better.  BTW, I bought my 600R DT880s when they made their splash here, and they are good cans, but I'm spending more time w/HD600s esp w/CTH.
 
Sachu - a lot of work went into Erik's CTH & even more into my "fancy" one.  Think spreading things out & shielded cables help make things more quiet than a std build.
BTW the pwr switch is a DPDT & breaks e12 relay pwr along w/24VAC in so there is no "click" @ pwr off.  Nice to hear the design @ its best but I really did it because of my closeness to the project.  
Here's another shot:

 

[Forte]

Quote:

BTW the pwr switch is a DPDT & breaks e12 relay pwr along w/24VAC in so there is no "click" @ pwr off.

 
Have you posted detail on how best to do this anywhere?
 
And how do those Russian caps sound compared to the Sonicaps?

 

[cfcubed]

Re: relay interrupt:  IIRC, I just used a dremel w/small bit or X-acto knife & cut away one of the under side traces to the relay coil...  Probably the Q3E/D3E junction to coil negative trace.  Then used a 2-lead section pulled from an old floppy cable, one lead on the orphan relay solder joint, one lead to Q3E/D3E junction before the break.      Like using wire set pulls from old, thicker floppy cables for light loads (see LED feed in pic above).
 
Re: caps - Wiatrob sent me those caps w/some CTH stuff I bought from him.  I like 'em & they are a good deal, but I can't say which is "better".  I think they soften the edge/treble a wee bit & that can be a good thing for the CTH.  But I really used them because I was out of Sonicaps, IOW not worth the trouble of swapping unless you want to play.
 
Quote:

Have you posted detail on how best to do this anywhere?
 
And how do those Russian caps sound compared to the Sonicaps?

 

[erikzen]

Quote:

I think its nearing that time where i need to build myself one of these fancy CTHs

New variant: FCTH

 

[royewest]

I know this probably belongs on the for-sale forum, but it's been so long I thought I'd post here where folks might remember what this is (mod's willing) -- the Spruce Canyon web site is gone...
 
I have a CTH kit from Spruce Canyon Labs I never built (got a new job just after it arrived and down the rabbit hole I went). Clearing up the office this afternoon I found it. Box has the 1.1 board, two tubes (Sovitek 6NP1 and RCA 12AU7A), the power supply, the replacement cap,black Hammond case (with tiny scratch on bottom), drilled perf and solid top with gaskets, knob, all the parts of course -- the works except for the custom front and back panels. The bag o' parts is unopened. Looking through old email I think this all came to something over $175.
 
If folks are interested, send me a PM and I'll try to get back on line here by next weekend.
 
Thanks,

__Roy

 

[cfcubed]

Yeah, if you still have that kit you should list it in FS forum... Think someone would grab it up as sourcing CTH parts is a bit more difficult now & requires differing vendor shipments.
 
Quote:

I know this probably belongs on the for-sale forum, <snip> I have a CTH kit from Spruce Canyon Labs I never built

 

[arteom]

I've been enjoying my CTH for some time now, ended up selling my x-can v8 after all and soon hopefully will start on a EHHA. But at the moment the cth is all I have. Just yesterday I received a pair of Audio Technica ATH-AD2000's, they sound great but with the CTH I get a very much audible hiss when the cans are plugged in, I get the hiss even with the volume all the way down, and it increases after about 1 o'clock on the pot. I don't turn the volume past 9 o'clock as it is plenty loud there. What can I do to make the CTH more suitable for these headphones? I have never taken the CTH past 1 o'clock, that was with my k501.

 

[cfcubed]

Try searching this thread & the "A Very..." thread for "hiss"...  Those AD2000's are pretty low impedance & high efficiency/sensitivity from what I can see:
http://www.audiocubes.com/product_info.php?products_id=1088
Some amps, like the CK²III, can have their gain adjusted (e.g. like 4X instead of its default 9X).  The only way we can reduce the gain of the CTH is by choosing a lower-gain tube, so consider locating a lower-gain tube (I recently posted a supported tubes list).   Another option is to raise your R18s to 100R->150R.  And another is to sell/change-out the amp or the headphones
Quote:

<snip>. Just yesterday I received a pair of Audio Technica ATH-AD2000's, they sound great but with the CTH I get a very much audible hiss when the cans are plugged in, I get the hiss even with the volume all the way down,  <snip>

 

[arteom]

*smacks self on head 

 
I had tried a bunch of 6922 tubes, tried it on 12v setting for heater with a hytron 12AU7 and no hiss. Woohoo.

 

[arteom]

and the hiss is back again, hmm.

 

[cfcubed]

If it seems to come & go then maybe you are hearing noise (e.g. due to a loose connection) not hiss due to too high a gain.
 
Quote:

and the hiss is back again, hmm.

 

[erikzen]

I have been hearing noise lately on my CTH.  I attribute it to switching to Grados for my listening.  With a Denon D5000 with Jenna Labs cable I heard no noise.  I've noticed that if the Grado cable comes too close to the power cord for the CTH PSU I get some ground hum.  This definitely comes and goes and is very dependent on component and wire proximity.

 

[aphexii]

oh HELL yea!
 
Bugle Boy 6DJ8's that i won on eBay just arrived, absolutely fan-FREAKING-tastic pairing with my ESW9's
 

 

[arteom]

Yeah, I needed to switch out the ICH recently and maybe need to check the soldering on that. 
 
Got a set of tubes myself just a few weeks back on ebay, got really lucky. Got one of each: Holland Amperex ecc88, Amperex PQ white label 7308 USA, Amperex PQ D Getter USA 6922, RCA West Germany 7308, and one mystery tube that perhaps outperforms all in resolution, though a little lacking in the bottom end. Have also a Siemens CCa I got a week before that. They really better the value of the CTH.