2. digital
  3. 151748-137352

CAL Alpha produces brutal gain

My system is made of Jolida 302  integrated tube amp , Thorens TD160 + Cambridge preamp and a tablet for simple MP3 background music.
About four speaker sets :AR,Vintage Jamo, Tannoy and Joseph audio.
I recently got a nice CAL Delta transport and Alpha tube DAC.
Everything works BUT , the output coming from the CAL DAC is aggressive. Cannot turn the volume knob over 8 o'clock. I am usually at 9-12 with all others.
The sound is compressed.
I have a very warm relaxed 3d listening set . The Alpha tube DAC seemed like a natural partner...

Anyone experienced such a thing ? 
Too much gain? 
Any idea? 
*Replaced the cables (rca and coax)
** Changed the input channels
*** Checked bias
**** What's next?????
Tnx
ehollander

Showing 1 response by georgehifi

georgehifi's avatar
georgehifi
10,312 posts
 
ehollander OP
My system is made of Jolida 302 integrated tube amp


This is probably your problem, this amp only needs 500mV (0.5v) in for full 50watt output.

The Jolida 302 is just a poweramp, with a passive volume control on the input, the gain could be lowered by a competent tube tech by changing the feedback resistor R5, but then C2 will have to change also so the filtering is the same. A good tech could do this in an 1hr and parts are a couple of dollars. 
http://www.drtube.com/schematics/jolida/sj-502a.gif


Or you can go the ugly way which can cause impedance matching problems that aren’t dangerous, and get two inline rca to rca attenuator.
http://www.rothwellaudioproducts.co.uk/html/attenuators.html

Cheers George
More to discover