I need your help to find a simple but very good sounding power amplifier!
I just need a couple of watt, 10 or more!
I saw a lot of Dynaco schematic on the net but I have no idea if there other good and simple design!
I will probably make two small mono-block.
The Dynaco ST-70 and ST-35 seem to be a "classic"? And what about the Mark serie?
Thank you
I just need a couple of watt, 10 or more!
I saw a lot of Dynaco schematic on the net but I have no idea if there other good and simple design!
I will probably make two small mono-block.
The Dynaco ST-70 and ST-35 seem to be a "classic"? And what about the Mark serie?
Thank you
You could buy a new dynakit here: Dynakitparts.com
There are a lot of possible driver upgrade kits you could purchase from various sources in conjunction with chassis and transformers from dynakitparts.. GeeK should be able to help on that score.
If you only need 10W or so you could build a single ended amp. These have about 1/2 the parts count (and price) of a Dynaco and arguable sound better.
But as your need for power goes up the push-pull design of the ST35/70 makes more sense. The ST35/70 is infinity "tweakable" so much so that if you use some of the available driver boards the end result shares little with the original design except the transformers and chassis.
Google will locate any number of ST70 schematics for you search on "st70 schematic" But,... There are so many version of this amp, all different. Triode's board imprements their version, there are many others. I really doubt you want to builld the original Dynaco version, finding the required tube is not easy. It is out of production. Some ST70 versions use more available 12ax7 or 12au7 tubes.
While technically the name "ST70" means just the amp as sold by Dynaco today we use the name ST70 to refer to a family of amps derived from the old ST70. So there is no one schematic
If you want to save some money on the transformers look into Edcor at
EDCOR - Products They are some good and less expensive OPTs
As for single ended, I thought I posted this earlier but here it is once more.
DIY Vacuum Tube (Valve) Amplifier Projects - Hi-Fi Audio
Look at the SE amps there. You will begin to see a patern as they are all the same design, more or less.
I would recommend as your first amp a small 5 to 10 WPC SE amp. Maybe one based on a 6V6 tube. The tubes are cheap and you can use a pair of $40 OP transformers, You can have a working amp for $200 and 1/2 the parts count of a push pull amp.
Push-pull is for when you need more power. How to determine how much power you need? Look at your speaker sensitivity then do some math. After working a few examples you will soon see that loudness depends more on speaker sensitivity than on power. For example my 5W amp and 101 dB speaker can be heard inside the house across the street. But my old Infinity speakers are maybe 83dB and requite a minimum of 50W and 100W is more reasonable for those speakers.
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