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I figured since I was always on this site I might as well join.
I have a few questions about a project I'm starting. I'm building a stereo amp based on on an old Harman Kardon HK250. This is my first from scratch project. I've only modded old organ amps before and decided it was time to really learn a few things. I'd like to use OPTs and a PT from some amps that I already have. I've measured the OPTs and they should work. The PT is a little overkill but I think it might work too. The amp will basicly be 4 PP circuits bridged into 2, with 4 OPTs and 1 PT
For the feed back loop the original schematic shows it coming off of the 16 ohm tap from the OPT. Can I use the 8 ohm tap instead? (the OPTs I'm using only have 8 ohm) or can I put an 8 ohm resistor in line to bring it back to 16?
I'm thinking about using a PT from a Conn amp that I have.
The orig. schem. says I need 150vac from the PT. My PT has a couple of taps that will give me 610vac. Can I use another transformer to step it down to 150ish?
Any ideas, comments?
Here's the HKs schem. http://www.rkamplifiers.com/hk250.pdf
I have a few questions about a project I'm starting. I'm building a stereo amp based on on an old Harman Kardon HK250. This is my first from scratch project. I've only modded old organ amps before and decided it was time to really learn a few things. I'd like to use OPTs and a PT from some amps that I already have. I've measured the OPTs and they should work. The PT is a little overkill but I think it might work too. The amp will basicly be 4 PP circuits bridged into 2, with 4 OPTs and 1 PT
For the feed back loop the original schematic shows it coming off of the 16 ohm tap from the OPT. Can I use the 8 ohm tap instead? (the OPTs I'm using only have 8 ohm) or can I put an 8 ohm resistor in line to bring it back to 16?
I'm thinking about using a PT from a Conn amp that I have.
The orig. schem. says I need 150vac from the PT. My PT has a couple of taps that will give me 610vac. Can I use another transformer to step it down to 150ish?
Any ideas, comments?
Here's the HKs schem. http://www.rkamplifiers.com/hk250.pdf