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DR103 Mid 70s

Posted: Fri Mar 10, 2023 7:53 pm
by phk200
Hello everyone. I finally got my hands on a Custom 100 from 1976. There aren't many for sale in Denmark. Therefore, I recently built a Custom 100 with early 70 circuits. They both sound fantastic and very similar despite small differences in the circuit. When I got hold of an original it would be fun to check the circuit with the ones that Mark Huss has made on Hiwatt.org At the same time I made a new layout as it is in my Serial 9490 I have long admired website hiwatt.org. It is a great site with a lot of information. I have found a few little things that I want to share here. I have allowed myself to redraw a little in the 2 drawings. in my DR103 there is no 47n Cathode cap on V2. Otherwise the circuit fits. There are 2 changes in some values that I have drawn on the diagram. 22n is 47n in my amplifier and V3 pin2 grid is 270k instead of 220k. I have also drawn a new layout based on your rev1,3 mid 70 I am attaching the pictures here. Many greetings, Peter Øvad Halkjær

Re: DR103 Mid 70s

Posted: Tue Mar 14, 2023 5:08 pm
by mhuss
hi Peter,

Thanks for the information.

There were many small changes year-to-year in part values and circuit tweaks as well. I've just captured representative examples on hiwatt.org. :D

--mark

PS. You need to get a proper Hiwatt cab too. :mrgreen:

Re: DR103 Mid 70s

Posted: Fri Mar 24, 2023 12:20 pm
by phk200
Hi Mark.
You are welcome. it was fun to do. And yes, i hope to find a Hiwatt Cabinet one day. So far there is a bit of a mix of Marshall cabinets with various Celestion units to play with :)