If the changes in the regulator result in no measurable change in the overall circuit's performance above -100dB, then the electrical signal at the output is unchanged to far less than the noise floor of any listening environment and more than any source material available. A claim of audibility of changes at that level would be an extraordinary one.
I don't make extraordinary claims without evidence. I leave that to the more fanciful folk.
Regulators are FAR more critical for cascode circuits like Allen's, where PSR is near zero.
I don't make extraordinary claims without evidence. I leave that to the more fanciful folk.
Regulators are FAR more critical for cascode circuits like Allen's, where PSR is near zero.
Hi Dxvideo, (just following up the email I sent),
I'm about to follow your adventures into the Cavalli OCL tube buffer and finally found this thread - I have read up on Sy's Heretical, too.
Could I ask if you did a final pcb and if so, did you add the extra "grid stopper" resistor and the "grid-to-ground" resistor as suggested by ZM?
A couple of other questions, if I may -
* Does the use of the 1N4148 work okay as a "replacement" for the LEDs, and is it used because of the use of the 6N6P valve, rather than the ECC99? What is the current thru the valve and also, the voltage across these diodes?
* Could you tell me the voltages Vcc and Vee, as the cct doesn't include the extra ZVNs (as the Rail CCS) in the original cct? Was this left out on purpose?
* From my perusal of the Vee supply, I wonder what AC voltage is used before the bridge and if the second regulator effects the Vee?
I will add these to your thread, but not sure if it's still active.
I have the "AnalogMetric" buffer (based on the 5670 tube) here but prefer the sound of the Croft Micro preamp (based on the ECC82 valve) - I expect this design &/or Sys, to be a significant improvement and it will be interesting to compare to the B1.
I'm about to follow your adventures into the Cavalli OCL tube buffer and finally found this thread - I have read up on Sy's Heretical, too.
Could I ask if you did a final pcb and if so, did you add the extra "grid stopper" resistor and the "grid-to-ground" resistor as suggested by ZM?
A couple of other questions, if I may -
* Does the use of the 1N4148 work okay as a "replacement" for the LEDs, and is it used because of the use of the 6N6P valve, rather than the ECC99? What is the current thru the valve and also, the voltage across these diodes?
* Could you tell me the voltages Vcc and Vee, as the cct doesn't include the extra ZVNs (as the Rail CCS) in the original cct? Was this left out on purpose?
* From my perusal of the Vee supply, I wonder what AC voltage is used before the bridge and if the second regulator effects the Vee?
I will add these to your thread, but not sure if it's still active.
I have the "AnalogMetric" buffer (based on the 5670 tube) here but prefer the sound of the Croft Micro preamp (based on the ECC82 valve) - I expect this design &/or Sys, to be a significant improvement and it will be interesting to compare to the B1.
May be a bit late answer...
But, three of my friends made that buffer accorded to my first posting.. I have listened two of them. And found very very satisfactory at first sight.. One of them was made with ordinary parts and the other was with audio grade parts (Dale RN60 resistors, Telefunken ECC99 tubes etc..). Both of them was successfull. However may be, have not dominant "tubelike" sound. Very very transparent and not colored. Inaudible distortion figure. Nearly zero DC offset (like 0,1 mV) with just TL082 opamp.
After that, I decided to handle the power supply. So this version was needed a special transformer (60, 15+15, 20, 6v3) which is not desirable. Then I have designed a more complex but needs only one standard (15+15) transformer PSU for Cavalli buffer.
And one of my friends implied that version of psu to his buffer.
In my listenning impressions of that new PSU, I found it very very silent! The old one was also very silent but this one is different. The sound was not different. But the noise figure was improved.
I willl post this new PSU soon.
Now I am planing to use that Cavalli buffer for my LM4702 + Lateral MOSFET amplifier. Which has only 6K2 input impedance! Do you think it will drive my amplifier without a significant problem?
Thanks in advance.
But, three of my friends made that buffer accorded to my first posting.. I have listened two of them. And found very very satisfactory at first sight.. One of them was made with ordinary parts and the other was with audio grade parts (Dale RN60 resistors, Telefunken ECC99 tubes etc..). Both of them was successfull. However may be, have not dominant "tubelike" sound. Very very transparent and not colored. Inaudible distortion figure. Nearly zero DC offset (like 0,1 mV) with just TL082 opamp.
After that, I decided to handle the power supply. So this version was needed a special transformer (60, 15+15, 20, 6v3) which is not desirable. Then I have designed a more complex but needs only one standard (15+15) transformer PSU for Cavalli buffer.
And one of my friends implied that version of psu to his buffer.
In my listenning impressions of that new PSU, I found it very very silent! The old one was also very silent but this one is different. The sound was not different. But the noise figure was improved.
I willl post this new PSU soon.
Now I am planing to use that Cavalli buffer for my LM4702 + Lateral MOSFET amplifier. Which has only 6K2 input impedance! Do you think it will drive my amplifier without a significant problem?
Thanks in advance.
Good to hear from you Ozgur,
I think it'll drive your 6k2 input impedance okay.
I have been sidetracked with Aikido ccts and been quite busy so no progress on the valve Xover so no progress with the OCL buffers either but ....
I did get a pcb for the high voltage Salas shunt Reg (known as SSHV) and from all accounts that I have seen, the simple version is really excellent and pcbs are available from the Cavalli website.
Someone told me that old TV sets often had good transformers in them that are about the right voltages - not the new ones.
Hope everything is going okay in these difficult times
... James
I think it'll drive your 6k2 input impedance okay.
I have been sidetracked with Aikido ccts and been quite busy so no progress on the valve Xover so no progress with the OCL buffers either but ....
I did get a pcb for the high voltage Salas shunt Reg (known as SSHV) and from all accounts that I have seen, the simple version is really excellent and pcbs are available from the Cavalli website.
Someone told me that old TV sets often had good transformers in them that are about the right voltages - not the new ones.
Hope everything is going okay in these difficult times
... James
Hi James,
Its good to hear from you too..
These are not good days I know. And everything is not OK.. I hope it changes in near future! It must be change because.
Anyway,
May be I will purchase some Salas PCB's like yours.
Or you may want to make my new PSU..
I can send you the PCB files if you interest.
I will report about the results (if I can make it soon
)
Take good care of you..
PS: May be I have some inspirations from Cavalli's old PSU designs for that circuit..
Its good to hear from you too..
These are not good days I know. And everything is not OK.. I hope it changes in near future! It must be change because.
Anyway,
May be I will purchase some Salas PCB's like yours.
Or you may want to make my new PSU..
I can send you the PCB files if you interest.
I will report about the results (if I can make it soon
)Take good care of you..
PS: May be I have some inspirations from Cavalli's old PSU designs for that circuit..
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just to refresh my memory,
Vdd,Vcc = B+ anode rail = -- volts?
Vee = -ve rail = -- volts
Vlo+/- are Opamp supply = 15 volts
Vlh are heaters supply and either 6/12 volts?
Vr1,Vr2 are ac input? and it's been multiplied up to the IC4 yes?
Now that I think I've got a handle on it, it seems quite a neat package of basic building blocks without earth loops and such - interesting.
There is a way to improve the performance of the 3 pin regs by adding a transistor to the control pin and a few bits - I'll see if I can find it and send it over to you.
I never got to see the power supplies he talked about for the OTL buffer - however, SY's rather clever design on the Heretical high voltage supply is worth a good look - quite simple and apparently it works pretty well.
One of the things I'm looking at with a small board for a hybrid amp is a delay of the B+ high voltage supply while the heaters have come up on the valves - playing around with maybe using fets as switches (like our familiar IRF610s, etc) instead of relays and dc protection o/p relays also. For the Moskido hybrid amp.
Glad to hear that the supply improved the sound so much and that the buffer is actually nearly transparent without extra flab, etc - I was worried about that part a bit.
Unfortunately, I'm still doing pcbs with a really old Protel program but would like to see your overlay and layout of the tracks to use here, thank you.
Yes, we are hoping things do get sorted out a bit better so we can start rebuilding some sort of future - out here, we are doing reasonably well but not sure if this will continue, particularly with the quality of our politicians! yuck!!
... James
Vdd,Vcc = B+ anode rail = -- volts?
Vee = -ve rail = -- volts
Vlo+/- are Opamp supply = 15 volts
Vlh are heaters supply and either 6/12 volts?
Vr1,Vr2 are ac input? and it's been multiplied up to the IC4 yes?
Now that I think I've got a handle on it, it seems quite a neat package of basic building blocks without earth loops and such - interesting.
There is a way to improve the performance of the 3 pin regs by adding a transistor to the control pin and a few bits - I'll see if I can find it and send it over to you.
I never got to see the power supplies he talked about for the OTL buffer - however, SY's rather clever design on the Heretical high voltage supply is worth a good look - quite simple and apparently it works pretty well.
One of the things I'm looking at with a small board for a hybrid amp is a delay of the B+ high voltage supply while the heaters have come up on the valves - playing around with maybe using fets as switches (like our familiar IRF610s, etc) instead of relays and dc protection o/p relays also. For the Moskido hybrid amp.
Glad to hear that the supply improved the sound so much and that the buffer is actually nearly transparent without extra flab, etc - I was worried about that part a bit.
Unfortunately, I'm still doing pcbs with a really old Protel program but would like to see your overlay and layout of the tracks to use here, thank you.
Yes, we are hoping things do get sorted out a bit better so we can start rebuilding some sort of future - out here, we are doing reasonably well but not sure if this will continue, particularly with the quality of our politicians! yuck!!
... James
My friends made some clones of that circuit.. Results are fairly good. No supply noise but may be some "hiss" is audible.. However it sounds more like solid state.. So if you prefer tube like sound I cannot advide t for you.. One of my friend uses it before LM4702+Lateral MOSFET amplifier for over one year and he's happy..
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