Circuit Board
Top View of the active circuitry. It is a circuit provided by Steve Eddy, his Tao headphone buffer. The rest of the 8 parts are on the bottom of the board.
This circuit has proven better than any other I have tried. Cleans the sound up and can drive anything.
Top View of the active circuitry. It is a circuit provided by Steve Eddy, his Tao headphone buffer. The rest of the 8 parts are on the bottom of the board.
This circuit has proven better than any other I have tried. Cleans the sound up and can drive anything.
Attachments
Inside the box
Power goes to a pair of 55,000 ufd Jensen 4 pole caps, and board has local bypassing and filtering. Both channels share the main suypply.
The output transformers are LO410 S & B. Left over from a disc player exercise. Big beefy chunks of iron.
The pots for now are stereo Alpha 50K stereo carbon, wired to make a 25K mono. Waiting on some log taper PEC to try.
Drive shafts had to be chopped to fit.
Power goes to a pair of 55,000 ufd Jensen 4 pole caps, and board has local bypassing and filtering. Both channels share the main suypply.
The output transformers are LO410 S & B. Left over from a disc player exercise. Big beefy chunks of iron.
The pots for now are stereo Alpha 50K stereo carbon, wired to make a 25K mono. Waiting on some log taper PEC to try.
Drive shafts had to be chopped to fit.
Attachments
Another angle
The box is from England, diecast aluminum. Lined with mu-metal. Cannot hurt, sitting between two power supplies on my rack.
Best of all, the sound is richer, better timbre, seems almost holographic.
Previous line was the same Tao buffer with out the Jensens, output transformers, and the lined box. It seems more sterile, less harmonic. If it is added distortion from the output iron, it sure is pleasant.
Listened to a 7500.00 linestqage at my home a month ago. It did not comparte well with the old unit. This new one even caught my wifes attention. She asked what I had done to the system. She very seldom comments on the sound coming from my room.
The box is from England, diecast aluminum. Lined with mu-metal. Cannot hurt, sitting between two power supplies on my rack.
Best of all, the sound is richer, better timbre, seems almost holographic.
Previous line was the same Tao buffer with out the Jensens, output transformers, and the lined box. It seems more sterile, less harmonic. If it is added distortion from the output iron, it sure is pleasant.
Listened to a 7500.00 linestqage at my home a month ago. It did not comparte well with the old unit. This new one even caught my wifes attention. She asked what I had done to the system. She very seldom comments on the sound coming from my room.
Attachments
In action as I type
Top to bottom,
Micro Seiki DDX-1000, OL-RB-250, Denon 103R
Pearl phono with built mc headamp
Pioneer TX-9100 with power supply and filter mods
Marantz SA-8260 with mucho mods
Linstage flanked with its power supply and one for Pearl.
Hiraga Le Monstre, original transistors, C-L-C-L-C power supply, 350,000 ufds of Jensen four pole caps. Seems like a lot for a 5 watt per channel amp.
George
Top to bottom,
Micro Seiki DDX-1000, OL-RB-250, Denon 103R
Pearl phono with built mc headamp
Pioneer TX-9100 with power supply and filter mods
Marantz SA-8260 with mucho mods
Linstage flanked with its power supply and one for Pearl.
Hiraga Le Monstre, original transistors, C-L-C-L-C power supply, 350,000 ufds of Jensen four pole caps. Seems like a lot for a 5 watt per channel amp.
George
Attachments
Better view
Steve,
That part is cropped out. Here is an inside shot of the business end. The 4 pole Jensens, LED buffering resistors, mumetal lining, jacks, and S & B LO 410 line transformers are shown better.
The S & B iron is very large for its use. The -3dB points are 10Hz and 3Mhz. This is loaded with 600 ohms, not 25K.
George
Steve Eddy said:Nice job, George!
I envy you. I couldn't work in such tight quarters as that without the whole thing being smashed to bits at some point.
Can't seem to spot the output iron in the photos. Am I missing something?
se
Steve,
That part is cropped out. Here is an inside shot of the business end. The 4 pole Jensens, LED buffering resistors, mumetal lining, jacks, and S & B LO 410 line transformers are shown better.
The S & B iron is very large for its use. The -3dB points are 10Hz and 3Mhz. This is loaded with 600 ohms, not 25K.
George
Attachments
Amps
I did run a mono pair of Tamps for a while. The preamp worked great. The low imput impedance of the T amps is no problem. I am now using a My_Reference amp. It is better than the T amps in my system.
The circuit can be found by seaching here for either Tao buffer or Eight Part Harmony. My current board has a 46 ohm resistor on bottom, a 20 ohm pot in series with a 28 ohm resistor inbtween the sa1837. The output is taken off the wiper of the pot.
With a 20 turn pot the dc can be dailed to 0.0 mv. This is plenty low. Those 410 transformers have a dcr of 38 ohms and seem to deal with up to 5 mv dc with no issues. I suspect a few ma will saturate them.
The circuit works great without transformer coupling. Used this circuit for a year without transformer coupling.
Line now has a pair of Cinemag CLM15/15B input transformers also. And the PEC log taper pots mentioned.
I have now built three of these boards. The layouts are getting better each time. This pays off in sound quality.
Good luck in constructing this great little buffer.
George
I did run a mono pair of Tamps for a while. The preamp worked great. The low imput impedance of the T amps is no problem. I am now using a My_Reference amp. It is better than the T amps in my system.
The circuit can be found by seaching here for either Tao buffer or Eight Part Harmony. My current board has a 46 ohm resistor on bottom, a 20 ohm pot in series with a 28 ohm resistor inbtween the sa1837. The output is taken off the wiper of the pot.
With a 20 turn pot the dc can be dailed to 0.0 mv. This is plenty low. Those 410 transformers have a dcr of 38 ohms and seem to deal with up to 5 mv dc with no issues. I suspect a few ma will saturate them.
The circuit works great without transformer coupling. Used this circuit for a year without transformer coupling.
Line now has a pair of Cinemag CLM15/15B input transformers also. And the PEC log taper pots mentioned.
I have now built three of these boards. The layouts are getting better each time. This pays off in sound quality.
Good luck in constructing this great little buffer.
George
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