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yagas 19th January 2006 04:50 PM

Heretical Unity Gain line stage PLUS a little gain ?
SY, I would like to see another thread on how to couple a gain stage to your "Heretical line stage" using the same techniques...
although time is limited and valuable ...


SY 19th January 2006 05:35 PM

It's very, very easy. Use a step-up transformer. A JT-11P-4 will give you about 3dB. The nice thing about the circuit setup is that you can optimize the load for nearly any transformer, so if you want more gain, just use a higher step-up. I did a quick trial with a Magnequest/Peerless 15095 and it worked very well, albeit with too much gain for me to reasonably use.

yagas 23rd January 2006 10:31 AM

Sorry for my delayed response...

Agree ... but can my phono stage drive a 10K input transformer ?


pinkmouse 23rd January 2006 10:36 AM

Depends on the output voltage/impedance of your phono stage. Do you have any details?

SY 23rd January 2006 12:20 PM

If it can't, it's not difficult to up the input impedance. What sort of phono stage are you using?

yagas 24th January 2006 09:55 AM

I use the cornet phono from Hagerman.

The output stage consists of 12AU7@175V@6mA
Output impedance is 1K
What about raising the output coupling cap to 8-9uf or to change the ccs to sink about 10 mA ?


SY 24th January 2006 11:35 AM

You don't have to change anything, it will work fine as-is. 10K is not an unreasonable load for a 12AU7 cathode follower, and if you want a higher load impedance anyway, the input shunt resistor of the Heretical can be increased.

yagas 24th January 2006 01:30 PM

Thank you

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