Sorry CV,
The ones I like are the 8E16Ds (the 0.1% ones) - thru hole, 3ppm/C - they call them "econistors" I think. Nothing wrong with the Caddocks, IMO, it's just that I like the sound of those ugly green things (they're 'magic' as Fet gate stoppers in the F5 too.)
I can't remember where I ended up using them now (bloody computer melt down!) but I'll get it back for the details
I also prefer the Isabellenhutte PBH power resistors to the Caddock MP930s for the power resistors, with the shunt regs as the power supplies and Ohno Crystal silver wire.
I'm pretty sure it wouldn't be hard to optomise the circuit in any direction - I did something weird and used a string of leds in place of the zeners and I found the capacitors choice across the 'led string' effected the sound quite a bit too.
The PRPs, and also the IRCs [TRW] are readily available from Homemade Electronics in the US - good guys
The ones I like are the 8E16Ds (the 0.1% ones) - thru hole, 3ppm/C - they call them "econistors" I think. Nothing wrong with the Caddocks, IMO, it's just that I like the sound of those ugly green things (they're 'magic' as Fet gate stoppers in the F5 too.)
I can't remember where I ended up using them now (bloody computer melt down!) but I'll get it back for the details
I also prefer the Isabellenhutte PBH power resistors to the Caddock MP930s for the power resistors, with the shunt regs as the power supplies and Ohno Crystal silver wire.
I'm pretty sure it wouldn't be hard to optomise the circuit in any direction - I did something weird and used a string of leds in place of the zeners and I found the capacitors choice across the 'led string' effected the sound quite a bit too.
The PRPs, and also the IRCs [TRW] are readily available from Homemade Electronics in the US - good guys
Yeah, you guys over there have such easy access to these good components and it makes us quite envious!!
This headamp is definitely on the list of your "great" designs, Patrick.
I know some guys get "hung-up" on the power consumption of some of the ClassA headamps (and amps, too) but the amount of power that you consume just driving your car to the S/market for your groceries, or picking up your kids from school, etc, makes the 40 watts for this guy pale into insignificance in comparison (NP mentioned something like this awhile back on his website, I think).
I had some rather outspoken, critical 'greenies' here last night driving their expensive, thirsty, 2 ton, V8 turbo SUV monstre (complete with individual tv for the kids!)
This headamp is definitely on the list of your "great" designs, Patrick.
I know some guys get "hung-up" on the power consumption of some of the ClassA headamps (and amps, too) but the amount of power that you consume just driving your car to the S/market for your groceries, or picking up your kids from school, etc, makes the 40 watts for this guy pale into insignificance in comparison (NP mentioned something like this awhile back on his website, I think).
I had some rather outspoken, critical 'greenies' here last night driving their expensive, thirsty, 2 ton, V8 turbo SUV monstre (complete with individual tv for the kids!)
> This headamp is definitely on the list of your "great" designs, Patrick.
Did I ever publish a "poor" design ?
Wait till you see my total solution.
Patrick
What do you mean by "total solution" Patrick? How it differs from DAO? Will it be able to drive a wider range of impedance?
Cross Feed Passive Filter plus Buffer.
Gain stage of 4 with no global feedback but very low distortion (for high ohmic phones).
Battery or Tx (passive) power supply.
All in a usually nice XEN Audio Case, about 252Hx120Wx210D.
Maybe a USB DAC, but likely to be external.
We ran out of space.
The DAO as it is now will drive anything down to 24R.
Though some might want a touch more gain, just for ease of mind.
Patrick
Gain stage of 4 with no global feedback but very low distortion (for high ohmic phones).
Battery or Tx (passive) power supply.
All in a usually nice XEN Audio Case, about 252Hx120Wx210D.
Maybe a USB DAC, but likely to be external.
We ran out of space.
The DAO as it is now will drive anything down to 24R.
Though some might want a touch more gain, just for ease of mind.
Patrick
Someone sent me a PM asking for a circlotron DAO circuit.
Firstly one has to realise that one can only run a balanced headamp when one is prepared to rewire the headphone completely.
Most standard headphones come with a 3-wire cable (right signal, left signal & common ground).
This will not work with a balanced head phone amp of any type.
Only a few headphones, e.g. the AK701, comes with a 4-wire cable.
Yes, I have a circlotron DAO circuit, but you will no doubt also want PCBs, power supply schematics, layouts, case, ......
Since I don't have time even to get the single ended DAO realised, and most people would not want to rewire their expensive phones, the balanced version will have to wait.
You can of course study the standard circuit of any circlotron follower on the inet, and replace the active device with the top half of the standard DAO.
i.e. take the top half of the DAO 2x and place them side by side, and you are there.
As to power supply, you can refer to Mike's article, or the circuit published in the forum by Joachim Gerhard as background information.
Just use the search function.
Sorry to disappoint. I am aware there are also many people waiting for the standard DAO.
I can only do so much in my free time.
Thank you for your interest nevertheless,
Patrick
Firstly one has to realise that one can only run a balanced headamp when one is prepared to rewire the headphone completely.
Most standard headphones come with a 3-wire cable (right signal, left signal & common ground).
This will not work with a balanced head phone amp of any type.
Only a few headphones, e.g. the AK701, comes with a 4-wire cable.
Yes, I have a circlotron DAO circuit, but you will no doubt also want PCBs, power supply schematics, layouts, case, ......
Since I don't have time even to get the single ended DAO realised, and most people would not want to rewire their expensive phones, the balanced version will have to wait.
You can of course study the standard circuit of any circlotron follower on the inet, and replace the active device with the top half of the standard DAO.
i.e. take the top half of the DAO 2x and place them side by side, and you are there.
As to power supply, you can refer to Mike's article, or the circuit published in the forum by Joachim Gerhard as background information.
Just use the search function.
Sorry to disappoint. I am aware there are also many people waiting for the standard DAO.
I can only do so much in my free time.
Thank you for your interest nevertheless,
Patrick
Hello all. Here is a try to make Circlotron scheme. Sure thhing I did many mistakes. Here are the questions. What direction should point J511 diode? And are the resistors values good and where the power ones are needed (3W for those 3.9 and 5.6 ?). Are trimmers in right place (assume they should be 1k pots)? Are connections for LU1014 and IRFP240 correct?
Schematic attached.
Best regards!
Alex
Schematic attached.
Best regards!
Alex
Attachments
a) I cannot delete anything you posted. Only you and moderators can.
b) It is an old schematics a few years back about a balanced DAO with TCS.
It has not been built by me or anyone else, and today I shall not post such schematics again.
c) Since it is from an earlier post and hence can still be downloaded by anyone, I don't quite see the purpose of posting again here.
d) As I said already, I don't have time to support any balanced DAO project that any of you might want to undertake. Please understand.
Cheers,
Patrick
b) It is an old schematics a few years back about a balanced DAO with TCS.
It has not been built by me or anyone else, and today I shall not post such schematics again.
c) Since it is from an earlier post and hence can still be downloaded by anyone, I don't quite see the purpose of posting again here.
d) As I said already, I don't have time to support any balanced DAO project that any of you might want to undertake. Please understand.
Cheers,
Patrick
Patrick
My apologies for posting a duplicate
I await your completion of the SE Total Solution
Best
Bob
I have been asked via PM about the DAO and where to get documentation, etc.
All information an experienced DIYer needs is in the forum, somewhat spread over in this thread and the links below :
http://www.diyaudio.com/forums/head...discrete-class-headphone-amp.html#post2594272
This is really a project for the more experienced builders, as are most of the XEN projects.
For the not-so-experienced DIYers who absolutely want to jump into the deep end,
we are preparing a total solution with full documentation where you can obtain most of what you need directly from us.
These include PCBs for DAO, crossfeed buffer, a HeadAmp Gains Stage (HAGS), CRC Power Supply & Rectifiers,
as well as matched transistors, and maybe resistors.
Components not supplied by us (transformer, PSU caps, switches & connectors, etc.) will be listed in a Bill of Material with at least one suggested source.
We are currently preparing the prototype. I expect it to be ready some time early 2013.
After that we shall organise a GB and then get enclosures (mini-tower) custom made.
So you should be looking at delivery to you in about 1 year from now.
If you cannot wait, just build as Steen and a few others did by P2P wiring.
You need to know what you are doing though.
Sorry for the long wait. Too many things to do.
But I am quite sure it will be worth the wait.
Patrick
All information an experienced DIYer needs is in the forum, somewhat spread over in this thread and the links below :
http://www.diyaudio.com/forums/head...discrete-class-headphone-amp.html#post2594272
This is really a project for the more experienced builders, as are most of the XEN projects.
For the not-so-experienced DIYers who absolutely want to jump into the deep end,
we are preparing a total solution with full documentation where you can obtain most of what you need directly from us.
These include PCBs for DAO, crossfeed buffer, a HeadAmp Gains Stage (HAGS), CRC Power Supply & Rectifiers,
as well as matched transistors, and maybe resistors.
Components not supplied by us (transformer, PSU caps, switches & connectors, etc.) will be listed in a Bill of Material with at least one suggested source.
We are currently preparing the prototype. I expect it to be ready some time early 2013.
After that we shall organise a GB and then get enclosures (mini-tower) custom made.
So you should be looking at delivery to you in about 1 year from now.
If you cannot wait, just build as Steen and a few others did by P2P wiring.
You need to know what you are doing though.
Sorry for the long wait. Too many things to do.
But I am quite sure it will be worth the wait.
Patrick
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I have again been asked by PM how relevant the matching is for the "matched" devices offered by Deep Surplus.
Deep Surplus claims to use the same matching method described by Nelson in his Zen V9 article :
http://www.passdiy.com/pdf/ZV9.pdf
While I have not bought and measured any from them, I had matched devices from Grey Rollins years ago that were matched using the same method.
http://www.diyaudio.com/forums/group-buys/71633-lovoltech-lu1014d-power-jfet.html
We have of course curved traced all of them under operating conditions of the DA headamp.
The results are described in the short article attached.
Conclusion: Perfect matching means buying 50~100 devices and curve trace them all, properly.
No short cuts !!!!!!!!
Patrick
Deep Surplus claims to use the same matching method described by Nelson in his Zen V9 article :
http://www.passdiy.com/pdf/ZV9.pdf
While I have not bought and measured any from them, I had matched devices from Grey Rollins years ago that were matched using the same method.
http://www.diyaudio.com/forums/group-buys/71633-lovoltech-lu1014d-power-jfet.html
We have of course curved traced all of them under operating conditions of the DA headamp.
The results are described in the short article attached.
Conclusion: Perfect matching means buying 50~100 devices and curve trace them all, properly.
No short cuts !!!!!!!!
Patrick
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