Jose Martins sent me an email with his recent built on the 27/56 preamplifier using the gyrator load and these PCBs. I recently posted an idea using the lovely 27 IHT valve here.
Here is a picture of the finished preamplifier:
Hello Ale,
Here is some photos of my new creation where I used your Gyrators boards.
This is a line 27/56 preamplifier. Working great with your Gyrator boards. I’m planning to use also in near future a second output with Magnequest parafeed transformers B7/15K.
I built this project in old Antique Sound Lab AQ2001 inox steel chassis that I have for some years in my garage.
The filament supply for tubes are regulated and noise of this preamplifier is very low even with old Arcturus 127 triodes from 1923. It is very important to connect the cathode of these old tubes to the filament.
I can also use 56 triodes to get more gain with no modification. Now I must test all my stock of 27 and 56 triodes. I’m very happy with the sound even compared with others DHT tube preamplifiers I have (26, 4P1L, VT-25, 1G4, RE084, Ba, Ca, TM2).
I’m very happy with your boards. Thank you for your great products.
Best Regards
José Martins
Ps: please excuse my bad English.
This preamp looks great, well don Jose. BTW: your English is really good, so nothing to apologise of. I hope to get some circuit diagrams and description from Jose to update the post. In the mean time, here are some detailed pictures of this fantastic build:
