Elektor featured a full length project based on this chip, also reprinted in their 302 Circuits book. Full Data can be found in the National Semiconductor site. I have a photocopy of the write-up and would be glad to send it to you. My address:
Dr. R. Shashidhar
Department of English
Mangala Gangothri -- 574 199
I tried the circuit and found it unbelievably quiet. The manufacturers, I thought, were for once justified in their claims. However the National people had nothing extensive on high frequency erasure in DC feedback tape head preamps.
By the way, is STK4036 available where you live? I read that this LSI has a fully complementary output stage and performs quite well in active cross over constructions.
I was considering the OPA 2134-based preamps. They have found favour with many DIYers.
I have not come across the STK chip you mentioned. The common ones are the 4141 and 4171 power amp ICs. If I stumble upon them, I will inform you.
My address is Vivek Phadnis, 8/9, 4th Cross, MT Layout, 13th Cross, Malleswaram, Bangalore-560003.
I have an LM 381-based preamp circuit with bass and treble controls from Electronics For You. I could send it over if you want.
Thanks Vivek. I have read about the preamp you have mentioned. But I have a different problem. Being an Indian Classical enthusiast, I am condemned to live with tapes for some foreseeable future. CDs in this genre are expensive and there are not many to choose from. Old Maestros are ruled out.
I am therefore still living in the 60-70s era when there was so much enthusiasm for good tape and tape-head preamps.
If you are a discrete-die-hard, you could consider an all transistor configuration which also appeared in Elektor. The write-up to this project suggests that several trans connected in parallel lower noise figure significantly. You could try this one out with necessary modification in NFB.
Was it you who suggested in one of the threads that TDA7294 sounds bad?
I do not have any information about the TDA chip though I do not mind trying it.
I am not a die-hard discrete fan. I am just looking at various pre-amps, both discrete and op-amp-based. I have one discrete circuit from EFY which I am considering. I shall keep you informed about any developments.