Hi all. I attached the schem of a tube/SS amp I have been working on. It would be used for headphones... I just want some comments from tube-minded folks. 
Values:
C1- 1uF
C2- 4.7uF
P1- 100k
Q1, Q2- 2N5484
R1- 1M
R2- 330
R3- 200k
R4- 100
R5- 820
R6- 1k
R7- 1k
R8- 200k
R9- 1k
R10- 18k
R11- 1k
R12- 100
R13- 10
gain of opamp=10... biased into "class a", and all that stuff. I understand that... just wonder about the tube section. Opamps will run on either +/-12V or +/-15V... lost my good tranny so I may have to settle for 12V.
The tube will be run at +/-42V, probably. Does everything look ok?
How do you think it would sound? I haven't really heard many good things about tube/SS hybrids, but some peopl use them... so I thought I'd check them out. Thanks
Values:C1- 1uF
C2- 4.7uF
P1- 100k
Q1, Q2- 2N5484
R1- 1M
R2- 330
R3- 200k
R4- 100
R5- 820
R6- 1k
R7- 1k
R8- 200k
R9- 1k
R10- 18k
R11- 1k
R12- 100
R13- 10
gain of opamp=10... biased into "class a", and all that stuff. I understand that... just wonder about the tube section. Opamps will run on either +/-12V or +/-15V... lost my good tranny so I may have to settle for 12V.
The tube will be run at +/-42V, probably. Does everything look ok?
How do you think it would sound? I haven't really heard many good things about tube/SS hybrids, but some peopl use them... so I thought I'd check them out. Thanks
Attachments
i'm interested in this too, kinda ....
suppposed i wanted to use a tube pre-amp with a solid state power amp i have to inject some "tube flava", would i not use something like trespasser_guy, ..except maybe tap off with a bypass cap at the anode, as opposed to the cathode?
i already did this when testing the pre-amp section of a simple 6bq5 triode strapped amp i built last week. ..but is this the correct way to do this
questions from a newbie
suppposed i wanted to use a tube pre-amp with a solid state power amp i have to inject some "tube flava", would i not use something like trespasser_guy, ..except maybe tap off with a bypass cap at the anode, as opposed to the cathode?
i already did this when testing the pre-amp section of a simple 6bq5 triode strapped amp i built last week. ..but is this the correct way to do this
questions from a newbie
Yes... but they all cost a fortune... if done right. And, this way, I would be able to build something I know how to build (the SS part) so in the event that the tube thing didn't work out, I still had a good SS headphone amp. Plus, I'd get to use up my OPA637s and BUFs. I would love an all tube, and was about to order the parts a few days ago... but talked myself out of it because I have never done it before, and the amount of money I'd sink in it is a lot to lose...
Trespasser -
I found you. Hehe, I am a web surfer from hell. In fact, I work for the devil himself.
Anyway, that is not true. Depending on how you implement the designs posted at HeadWize, you can build a "decent" amp for about 200~300 USD. I would recommend having 100 USD on top of that on reserve.
Power Tranny: 50~100 USD
Tubes (Quad Dual Matched): 50~100 USD
Electronic Misc (Rectifiers, Resistors, etc): 50~100 USD
Hardware Misc (Sockets, Jacks, Chasis, etc): 10~30 USD
Reserve Components: ~100USD
Total: 260~330 USD + ~100 USD
That is for Kurt Strain's amp. I believe you can build an another amp for the same topology using 5687 Black Plates.
Eric Barbour's amp has the same topology but uses 6SN7/12SN7 which probably cost approximately 50 USD more. (includes sockets as well)
EarMax Clone should cost about the same.
Andrea's designs uses E182CC which is very difficult to find. ... 7119 is supposedly more available equivalent.
Premium Tranny Coupled Headphone Amps will cost you approximately 100~200 USD more.
NOTICE: This is when you go cheap.
Hybrid SRPP is very interesting. I recall someone had a kit designed Allen Kimmel.
Don't complain about having too much OPA637 and BUF634. No one told you to buy that much. ... Hey it's your money, and you burned it semi-foolishly. ... But hey, it happens. For example, I have a quarter mile of hookup wire. (But you don't hear me complaining. I am proud of it.)
Tomo
I found you. Hehe, I am a web surfer from hell. In fact, I work for the devil himself.
Anyway, that is not true. Depending on how you implement the designs posted at HeadWize, you can build a "decent" amp for about 200~300 USD. I would recommend having 100 USD on top of that on reserve.
Power Tranny: 50~100 USD
Tubes (Quad Dual Matched): 50~100 USD
Electronic Misc (Rectifiers, Resistors, etc): 50~100 USD
Hardware Misc (Sockets, Jacks, Chasis, etc): 10~30 USD
Reserve Components: ~100USD
Total: 260~330 USD + ~100 USD
That is for Kurt Strain's amp. I believe you can build an another amp for the same topology using 5687 Black Plates.
Eric Barbour's amp has the same topology but uses 6SN7/12SN7 which probably cost approximately 50 USD more. (includes sockets as well)
EarMax Clone should cost about the same.
Andrea's designs uses E182CC which is very difficult to find. ... 7119 is supposedly more available equivalent.
Premium Tranny Coupled Headphone Amps will cost you approximately 100~200 USD more.
NOTICE: This is when you go cheap.
Hybrid SRPP is very interesting. I recall someone had a kit designed Allen Kimmel.
Don't complain about having too much OPA637 and BUF634. No one told you to buy that much. ... Hey it's your money, and you burned it semi-foolishly. ... But hey, it happens. For example, I have a quarter mile of hookup wire. (But you don't hear me complaining. I am proud of it.)
Tomo
If you want the tube to sound like a tube, wire it as a voltage amplifier:
Yes, a 6DJ8 will run on a 12V plate supply. "Poorly" in the sense that maximum output will be very small, but plenty to drive your hot output stage (in fact I reduced the gain around the chips).
An externally hosted image should be here but it was not working when we last tested it.
Yes, a 6DJ8 will run on a 12V plate supply. "Poorly" in the sense that maximum output will be very small, but plenty to drive your hot output stage (in fact I reduced the gain around the chips).
> The 10K plate load resistor can be replaced with a 1.2mA CCS.
Sure, but for goodness sakes why?
It increases gain, which we already have too much of. It significantly decreases bias stability and tube interchangability (with the 10K, almost any small triode will work, but a 12AU7 won't even pass 1.2mA at 12V). It does very little to distortion. And it costs a dollar more, and TG is a poor broke student. And IMHO it decreases "tube sound", which is what he is looking for.
> wonder how well the 6DJ8 takes a line level source with its grid at Vg=0.
Maybe I went too far there, no cathode resistor. But it will work. Note that it is NOT at "line level", it is behind the volume control. I've assumed that TG will only advance the volume pot enough to drive the chips to desired volume (or that he accepts the sweet fuzz when pushed too far). With the chip gain I show, the tube puts out about 1V pk for a loud level. The grid signal voltage is about 100mV pk. Yes, the grid draws some current on peaks, but not much. And zero-biasing a triode is sorta necessary when the plate voltage is so very low.
But you might also try it with a 1K cathode resistor.
Sure, but for goodness sakes why?
It increases gain, which we already have too much of. It significantly decreases bias stability and tube interchangability (with the 10K, almost any small triode will work, but a 12AU7 won't even pass 1.2mA at 12V). It does very little to distortion. And it costs a dollar more, and TG is a poor broke student. And IMHO it decreases "tube sound", which is what he is looking for.
> wonder how well the 6DJ8 takes a line level source with its grid at Vg=0.
Maybe I went too far there, no cathode resistor. But it will work. Note that it is NOT at "line level", it is behind the volume control. I've assumed that TG will only advance the volume pot enough to drive the chips to desired volume (or that he accepts the sweet fuzz when pushed too far). With the chip gain I show, the tube puts out about 1V pk for a loud level. The grid signal voltage is about 100mV pk. Yes, the grid draws some current on peaks, but not much. And zero-biasing a triode is sorta necessary when the plate voltage is so very low.
But you might also try it with a 1K cathode resistor.
Hi,
Ah, well for one thing it increases both linearity and optimises u.
I realise the latter isn't welcome but we're already reducing the gain of the OPA so by reducing it some more I reckon the linearity of the whole circuit may benefit.
Granted, the circuit might end up actually starting to sound good... which is not what we're after either.Too bad.
I disagree, the 6DJ8 and its relatives (ECC86 come to mind at those plate voltages) are amongst the few glass amps I know of that show great linearity in such application.
I.e. Vg= 0.
For the fun of it I once hooked up my MC Hammer headamp to a CDP without attenuation at all and was surprised how well it handled large signals...not that it would make a great preamp but I guess you get the picture.
Oh, yes it sounded too lush and warm to be neutral, BTW.
As for the cost of adding a CCS, heck what do an MPS A14 and a BF245 cost nowadays? I'm sure there must be CCDs out there that deliver 1.2 mA for peanuts too.
Agreed and I can't be bothered with a little current draw either knowing that the source wil be capacitively coupled in 9/10 of the cases anyway.
Don't get me wrong on this one, I'm not looking for an argument...just looking at alternative inroads.
BTW, it's nice to see someone as knowledgeable as yourself contributing to this community, refreshing if I may say so.
Cheers,
Ah, well for one thing it increases both linearity and optimises u.
I realise the latter isn't welcome but we're already reducing the gain of the OPA so by reducing it some more I reckon the linearity of the whole circuit may benefit.
Granted, the circuit might end up actually starting to sound good... which is not what we're after either.Too bad.
I disagree, the 6DJ8 and its relatives (ECC86 come to mind at those plate voltages) are amongst the few glass amps I know of that show great linearity in such application.
I.e. Vg= 0.
For the fun of it I once hooked up my MC Hammer headamp to a CDP without attenuation at all and was surprised how well it handled large signals...not that it would make a great preamp but I guess you get the picture.
Oh, yes it sounded too lush and warm to be neutral, BTW.
As for the cost of adding a CCS, heck what do an MPS A14 and a BF245 cost nowadays? I'm sure there must be CCDs out there that deliver 1.2 mA for peanuts too.
Agreed and I can't be bothered with a little current draw either knowing that the source wil be capacitively coupled in 9/10 of the cases anyway.
Don't get me wrong on this one, I'm not looking for an argument...just looking at alternative inroads.
BTW, it's nice to see someone as knowledgeable as yourself contributing to this community, refreshing if I may say so.
Cheers,
An all tube design would be nice... but, I still feel that I don't know quite enough about them for m to attempt to build an amp... I mean, with the high voltages and hum issues I hear of, it is a bit unnerving to me at times. I am just afraid that I will sink $200 into an amp and have it not work well or not work at all. I realize everyone has to start somewhere, but losing $200 is not a good pace for me to start right now.
Anyway, would the plate resistor value stay the same if I increased V+ (or would you call it B+ since it is a tube...) to 15V? I really feel that the OPA637 would handle better on +/-15V.
My thoughts on building an SS amp with a tube up front were that if for some reason the tube didn't work out and sound good, then I could just toss it out of the circuit and bypass it, using only the SS portion for amplification and accept the losses of about $20 for tube and all.
PRR- that design does make more sense... hehe... I don't know what I was thinking when I drew it the other way.
Really, I don't know if it is the 'tube sound' I am after. What I heard and want to recreate is a very detailed, precise sound. I just upgraded my interconnects (made them myself) and the detail level increased 10-fold. If I could just get a little more smoothness or something out of it.... my amp is good, but not the best, and I just wanted to 'max out' on the headphone amp deal. While doing so, I thought I might use up some of my spare parts (ie OPA+BUF). For some reason, it seems to me that tubes are just more detailed. I don't know if I am correct in assuming that... but I might just give this a try to see how it goes.
Would it be likely to sound pretty darn decent? Or would it be subject to distortions presented by the tube? Thanks all
Anyway, would the plate resistor value stay the same if I increased V+ (or would you call it B+ since it is a tube...) to 15V? I really feel that the OPA637 would handle better on +/-15V.
My thoughts on building an SS amp with a tube up front were that if for some reason the tube didn't work out and sound good, then I could just toss it out of the circuit and bypass it, using only the SS portion for amplification and accept the losses of about $20 for tube and all.
PRR- that design does make more sense... hehe... I don't know what I was thinking when I drew it the other way.
Really, I don't know if it is the 'tube sound' I am after. What I heard and want to recreate is a very detailed, precise sound. I just upgraded my interconnects (made them myself) and the detail level increased 10-fold. If I could just get a little more smoothness or something out of it.... my amp is good, but not the best, and I just wanted to 'max out' on the headphone amp deal. While doing so, I thought I might use up some of my spare parts (ie OPA+BUF). For some reason, it seems to me that tubes are just more detailed.
I don't know if I am correct in assuming that... but I might just give this a try to see how it goes.Would it be likely to sound pretty darn decent? Or would it be subject to distortions presented by the tube? Thanks all
hehe... I was confused what I was after as well.
Just a few weekends ago, I was in Morton, IL for a family visit, so my dad and I stopped in SAS Audio Labs to hear a few tube amps. We listened to a pair of his PP monoblocks. What got me was the amazing detail and clarity through all ends of the spectrum. Cymbols were very clear and precise, very musical, if you will. It sounded real, I suppose. Very precise imaging, etc. It was unlike anything I have heard from an SS amp.
Right now, my headphone amp is a Jung multiloop with OPA2132P and BUF634. It is mid-fi, I guess you could say. I wanted to go with OPA637 and better components for the next one to be a higher end amp. A few days ago, I upgraded my input cables, as I said previously. The sound was immediately different, and closer to the sound I heard from the monoblocks than I have ever been before with my own equipment. More clear, highs are pretty and musical, cymbol crashes are lifelike, mids are beautiful, and bass is a tad punchier and more clear (nothing gets lost in the presentation- each element is present). I am sure you all know what I am talking about... you have all been into audio longer than I have.
Anyway, it always seemed to me that detail and clarity was in tubes... from what I have read by people here and other places. I am after the highest quality sound I can get, basically. I do most of my music listening through my headphones for hours on end. I am listening right now, and probably still will be at 2:00 tommorrow morning. So... if that helps any... I am a confusing person. hehe
EDIT: Steve- I was thinking it wouldn't do well on that low of a supply, which is why I had it on a dual supply instead of grounding it. I am using dual for opamps, if I grounded the cathode of the tube, would I need a separate rectifier and ground the - output? Then use that for the tube only?
Just a few weekends ago, I was in Morton, IL for a family visit, so my dad and I stopped in SAS Audio Labs to hear a few tube amps. We listened to a pair of his PP monoblocks. What got me was the amazing detail and clarity through all ends of the spectrum. Cymbols were very clear and precise, very musical, if you will. It sounded real, I suppose. Very precise imaging, etc. It was unlike anything I have heard from an SS amp.
Right now, my headphone amp is a Jung multiloop with OPA2132P and BUF634. It is mid-fi, I guess you could say. I wanted to go with OPA637 and better components for the next one to be a higher end amp. A few days ago, I upgraded my input cables, as I said previously. The sound was immediately different, and closer to the sound I heard from the monoblocks than I have ever been before with my own equipment. More clear, highs are pretty and musical, cymbol crashes are lifelike, mids are beautiful, and bass is a tad punchier and more clear (nothing gets lost in the presentation- each element is present). I am sure you all know what I am talking about... you have all been into audio longer than I have.
Anyway, it always seemed to me that detail and clarity was in tubes... from what I have read by people here and other places. I am after the highest quality sound I can get, basically. I do most of my music listening through my headphones for hours on end. I am listening right now, and probably still will be at 2:00 tommorrow morning.
So... if that helps any... I am a confusing person. heheEDIT: Steve- I was thinking it wouldn't do well on that low of a supply, which is why I had it on a dual supply instead of grounding it. I am using dual for opamps, if I grounded the cathode of the tube, would I need a separate rectifier and ground the - output? Then use that for the tube only?
I think I see
Trespasser, I think I understand what you are doing. Correct me if I am wrong.
You are running one supply, plus and minus, to lower costs, and that is why you were running plus and minus on the tube as well.
Well, it probably won't sound as good, but you can always improve on it later, when time and money are more abundant.
Don't worry about things. If you can, lay it out with plenty of room so you can impliment new ideas later.
By the way, the CF will always have a gain of less than unity.
Remember, this is your first tube project, so have fun and Enjoy yourself. ('
')
PS. I got the new speakers, which make the speakers you heard sound just ok.
Take care and good luck Trespasser.
Pss. "I am using dual for opamps, if I grounded the cathode of the tube, would I need a separate rectifier and ground the - output? Then use that for the tube only?
You would need an entirely new supply just for the tube. You can always add that later if you leave enough room on the chassis.
Trespasser, I think I understand what you are doing. Correct me if I am wrong.
You are running one supply, plus and minus, to lower costs, and that is why you were running plus and minus on the tube as well.
Well, it probably won't sound as good, but you can always improve on it later, when time and money are more abundant.
Don't worry about things. If you can, lay it out with plenty of room so you can impliment new ideas later.
By the way, the CF will always have a gain of less than unity.
Remember, this is your first tube project, so have fun and Enjoy yourself. ('
')PS. I got the new speakers, which make the speakers you heard sound just ok.
Take care and good luck Trespasser.
Pss. "I am using dual for opamps, if I grounded the cathode of the tube, would I need a separate rectifier and ground the - output? Then use that for the tube only?
You would need an entirely new supply just for the tube. You can always add that later if you leave enough room on the chassis.
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