I'll definitely try with both and report my observations. My player is pretty advance now with 24 decent regs ( like SPower) including 6 on the dos (when I build and fit it!!!).
Just need to speak to Lee about some 2sk170's and I'll have everything I need!!! Can borrow some off my old dos to start with ;-)
Just need to speak to Lee about some 2sk170's and I'll have everything I need!!! Can borrow some off my old dos to start with ;-)
Looks great, Ant. I copied your dual stripboard layout to build mine - I found that really helpful - cheers.
Ricardo, yes I did increase those cap values a few months ago. Perpetual motion only started after fitting the decoder regs, but it's possible something else happened in the process.
Ricardo, yes I did increase those cap values a few months ago. Perpetual motion only started after fitting the decoder regs, but it's possible something else happened in the process.
I put a musical fidelity X10D clone on the back of my TDA1541 and it was crap!
With valves, it very much depends on the design. unless you are using top flight implimentation, it wont work.
My Audio Aero has a valve output stage and although its very very good, I'm still not 100% convinced.
Go DOS in the 63 with decent components if you want something special. Rays boards are pretty cheap. Thats the route I'm taking
With valves, it very much depends on the design. unless you are using top flight implimentation, it wont work.
My Audio Aero has a valve output stage and although its very very good, I'm still not 100% convinced.
Go DOS in the 63 with decent components if you want something special. Rays boards are pretty cheap. Thats the route I'm taking
Hi, i'm back
Good to see there's plenty DOS-talk around
Seems the current sink needs some experimenting? Theoretically, it should be an improvement over a resistor. Maybe i'll implement a transistor-LED version in the next batch of boards, just like the one in the input stage. This would be even more versatile, and more easy to tweak to the correct current.
I'm glad you sorted out the sound now, Brent and others. Is it possible you guys could test the board with such a current sink? It's fairly simple to do: replace the FET T7 by a BC550C, replace the 100R resistor (R13) by a LED and insert a 10k resistor from the LED's anode to the +12V. R14 sets the current, it should be around 100R for 10mA to flow through the output buffer.
If you want to do it really quick-and-dirty you could even use the LED's voltage from the input stage and tie T7 base to T5 base.
Ray
Good to see there's plenty DOS-talk around
Seems the current sink needs some experimenting? Theoretically, it should be an improvement over a resistor. Maybe i'll implement a transistor-LED version in the next batch of boards, just like the one in the input stage. This would be even more versatile, and more easy to tweak to the correct current.
I'm glad you sorted out the sound now, Brent and others. Is it possible you guys could test the board with such a current sink? It's fairly simple to do: replace the FET T7 by a BC550C, replace the 100R resistor (R13) by a LED and insert a 10k resistor from the LED's anode to the +12V. R14 sets the current, it should be around 100R for 10mA to flow through the output buffer.
If you want to do it really quick-and-dirty you could even use the LED's voltage from the input stage and tie T7 base to T5 base
.Ray
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This is the X10D clone in the CD960. I upgraded all the elco's to larger value panasonic FC and replaced the film caps with Mundorf Supreme (after this picture was taken). The main output caps were mounted on the back of the player and were rather large 4.7uF supremes! The valves were cryo treated but I cant remember which ones! The I/V was burson with simple mica/RC55Y feedback filter. That was it from the DAC out. I tried with and without the valve stage and binned it off in the end. I stayed with just the Burson I/V & filter for everything I did with the various TDA1541 output stages since.
The Aero uses minature 6021w valves and the design is much better but still falls somewhat short of what most valve enthusiasts would call "good". Mine is not the factory SE but I've got the 0.22uF supremes alone with replacement std valves and several opamp changes to the output circuit. I've also just ordered a couple of relays so I can remotely switch the whole valve stage in and out.
The Aero uses minature 6021w valves and the design is much better but still falls somewhat short of what most valve enthusiasts would call "good". Mine is not the factory SE but I've got the 0.22uF supremes alone with replacement std valves and several opamp changes to the output circuit. I've also just ordered a couple of relays so I can remotely switch the whole valve stage in and out.
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Hi, i'm back
Good to see there's plenty DOS-talk around
Seems the current sink needs some experimenting? Theoretically, it should be an improvement over a resistor. Maybe i'll implement a transistor-LED version in the next batch of boards, just like the one in the input stage. This would be even more versatile, and more easy to tweak to the correct current.
I'm glad you sorted out the sound now, Brent and others. Is it possible you guys could test the board with such a current sink? It's fairly simple to do: replace the FET T7 by a BC550C, replace the 100R resistor (R13) by a LED and insert a 10k resistor from the LED's anode to the +12V. R14 sets the current, it should be around 100R for 10mA to flow through the output buffer.
If you want to do it really quick-and-dirty you could even use the LED's voltage from the input stage and tie T7 base to T5 base
Ray
Did you try with and without Ray?
Also, did you see my question about the transistors used? Could a BC640 be used in place of the 560?
No, not yet. I'm just back from my holiday
. It was horrible, no wireless internet in the forest Plus that i'm happy with the sound of the CFP-DOS so far, in my SA8400. But that doesn't mean there's no room for improvement
The BC640 is a 1A-current device, with much lower gain than the BC547...560 series. Not recommended. But you could use the BC556, 557, 558 or 559 as long as they are 'C' class with high gain. The 549/550 and 559/560 are low noise, that's why I picked them.
Ray
I noticed on the previous page that there was mention of valve output stages.
There are some well designed professional (studio) grade pre-amp's on the market using 12AX7 valves. These pre-amps come with the usual line-level (and Hi-Z Mic) inputs, phase adjustment and Class A/B variable biasing if you want to, amongst other pro grade adjustments.
These pre's start at around the €40 and go up to €400 depending on what you are looking for. I know they may be a bit over board but I was wondering if anyone had tried something like this on their output stages ?
All the valve heater circuits etc are sorted for you and some offer Class A - B variable output biasing and other pro-grade options for tweaking. Anybody got any comments on this ?
Cheers guys
Gareth
There are some well designed professional (studio) grade pre-amp's on the market using 12AX7 valves. These pre-amps come with the usual line-level (and Hi-Z Mic) inputs, phase adjustment and Class A/B variable biasing if you want to, amongst other pro grade adjustments.
These pre's start at around the €40 and go up to €400 depending on what you are looking for. I know they may be a bit over board but I was wondering if anyone had tried something like this on their output stages ?
All the valve heater circuits etc are sorted for you and some offer Class A - B variable output biasing and other pro-grade options for tweaking. Anybody got any comments on this ?
Cheers guys
Gareth
I tried that once, I used a differential stage with a double triode instead of the two FET's of the DOS. It sounded very nice, but I dare to say that the solid-state version sounds at least as good. Given the fact that tubes need a high voltage supply (= extra transformer) and a heater supply (= another extra transformer) and the solid state version runs on a comfortable +/- 15V or so, I chose the FET's. But it looks very cool
Doesn't matter what file-type, as long as it's clear
Regards,
Ray
Attachments
P122 is a bit general, isn't there a specific error number in the display? There's a list in the service manual, maybe this can point you in the right direction.
Ray
