fdegrove said:
And so he snubbs aside greenhorns with no ears for music :
Nelson Pass, Dan D', Mark Levinson, Bill Jonhnson, John Curl, Ken Ishiwata, Bruce 'Halcro' Candy, David Hafler, John Bedini, to name a few.
So what kind of music do you listen to ? Recorded by valve DATs,
mixed by valve consoles, using valve microphone preamps ? Your
CD player has of course valve D/A converter and digital filter, and
your valve radio only picks the stations transmitted using pure
valve audio chain ? All your records are only direct cuts using 100% valve equipment, right ?
What planet do you live on ?
And talking about fingerprinting, those tiny signals people retrieve from unimaginably distant quasars and protogalaxies from the edge of the universe are routinely amplified by -guess what- semiconductors. Wonder why silly astronomers don't listen to experienced Frank and use 'nonfingerprinting' valves ?
Sure. So reliable that all critical aerospace missions are controlled purely by valve equipment. When you fly a commercial flight you can rest assured that everything on that plane is controlled by valves, and flight control of course uses valve computers to avoid collision courses. And if course the whole internet network we use to write and read this is running on valves. Important modules in your car like engine management, ABS, airbag depolyment are all controlled by reliable valves ...
Yeah, sure.
The only meaningful sentence so far ! "Supposed" ...
Please, spare us.
fdegrove said:Hi,
I will...if you really MUST display your ignorance than be my guest...
Just don't expect any respect from me though.
Cheers,
Geez. I won't sleep tonight then.
You are part of a selected few who manage to post meganumber of posts to this forum and still not add one iota of useful information. Unless snide remarks, self glorification, 'me too's and empty condescension start to count as useful.
The vaccum actually suits you very well, Frank.
Brett said ...
Actually I thought that once but it just ain't so with good design and layout.
I think everything has to be relative to price. The K&K kit is fantastic VFM from all accounts. Kevin also seems a genuine guy willing to help. You just couldn't do it all tube for the price consistantly IMHO. Note it also has SS bits in the PSU. To get the same or better performance with iron is gonna cost you waaay more, be heavier, bulkier and that isn't for everyone.
Phono stages are no picnic to design never mind build so a kit has to be the way to go first up - success breads confidence. I remember how many failures I had in the beginning building these things - there were no forums, net etc to help. There are precious few books on how to esp valve designs.
Do get back to us with your reaction to it.
Actually I thought that once but it just ain't so with good design and layout.
I think everything has to be relative to price. The K&K kit is fantastic VFM from all accounts. Kevin also seems a genuine guy willing to help. You just couldn't do it all tube for the price consistantly IMHO. Note it also has SS bits in the PSU. To get the same or better performance with iron is gonna cost you waaay more, be heavier, bulkier and that isn't for everyone.
Phono stages are no picnic to design never mind build so a kit has to be the way to go first up - success breads confidence. I remember how many failures I had in the beginning building these things - there were no forums, net etc to help. There are precious few books on how to esp valve designs.
Do get back to us with your reaction to it.
Hi,
Since this is about a phono preamp for a cartridge with an output level that's on the lowish side to be taken in by an average MM phono pre, we face a noise/voltage amplication dilemma.
Many designers resort to adding a transistor at the input.
Personally, read that again: personnally, I feel this compromises my design philosophy to the point of not bothering with that approach.
This forum being about DIY, I fail to see why we can't circumvent the obstacles the average manufacturer has to to make the product profitable.
One way to go about is to use iron, yes, a step-up xf.
Let's face it, it can't be that hard to make a good step-up xf to lift the voltage from that MC to usable levels for our MM preamp, right?
Well, it ain't that simple after all. They all have a tendency to sound fine with one cartridge but not necessarily with another...still much better than most hybrid solutions to my ears.
So, what else can you do?
Well, what we need is a good I/V convertor which is where the ECC88 family really shines except for noise, Johnson noise that is.
What can we do to tackle that?
Paralelling triodes is one way, making sure all triodes are perfectly matched and selected for very low noise is another.
Now we can consider using chokes as plate loads or better still look at a CCS to isolate our tubes from PS vagaries.
We can even consider battery supplies for lowest PS noise and so on.
Can't be done? Paralleled tubes sound blurred?
Can be done and no they won't sound blurred, just have them carefully matched...we're working at mV levels here.
At the end of the day you may just end up with a very expensive system to run optimally but to me it's worth it.
After all, it's your system and you saved thousands by building it yourself already.
Will it measure as well as a SS system?
Maybe not, but it sure would let the music remain what it was intended to be; enjoyable.
Cheers,
Since this is about a phono preamp for a cartridge with an output level that's on the lowish side to be taken in by an average MM phono pre, we face a noise/voltage amplication dilemma.
Many designers resort to adding a transistor at the input.
Personally, read that again: personnally, I feel this compromises my design philosophy to the point of not bothering with that approach.
This forum being about DIY, I fail to see why we can't circumvent the obstacles the average manufacturer has to to make the product profitable.
One way to go about is to use iron, yes, a step-up xf.
Let's face it, it can't be that hard to make a good step-up xf to lift the voltage from that MC to usable levels for our MM preamp, right?
Well, it ain't that simple after all. They all have a tendency to sound fine with one cartridge but not necessarily with another...still much better than most hybrid solutions to my ears.
So, what else can you do?
Well, what we need is a good I/V convertor which is where the ECC88 family really shines except for noise, Johnson noise that is.
What can we do to tackle that?
Paralelling triodes is one way, making sure all triodes are perfectly matched and selected for very low noise is another.
Now we can consider using chokes as plate loads or better still look at a CCS to isolate our tubes from PS vagaries.
We can even consider battery supplies for lowest PS noise and so on.
Can't be done? Paralleled tubes sound blurred?
Can be done and no they won't sound blurred, just have them carefully matched...we're working at mV levels here.
At the end of the day you may just end up with a very expensive system to run optimally but to me it's worth it.
After all, it's your system and you saved thousands by building it yourself already.
Will it measure as well as a SS system?
Maybe not, but it sure would let the music remain what it was intended to be; enjoyable.
Cheers,
Frank
For what it's worth here is my experience. Ok, this forum would not be worth much if we agreed upon everything
I really have no experience with modern MC transformers with nickel or amorhous cores but i have had quite a few high-end (>$1000) commercial transformers and have liked none. Yes, i understand that one may prefer the homogenised sound a transformer offers in this application on the grounds of musicality, but the reduction of perceived resolution is just too much for me.
A lowly 2sk170 with battery power and good quality passives sounds really better to me without a trace of SS hardness, glare or lack of colour. If anything some transformers contribute more solid-stateness to the sound then the fet. Would i prefer it to a similarly built ECC88 stage? Difficult question, but when dealing with less than 0.5mV the ECC88 gets a bit noisy.
Paralleling? Of course it blurs the sound even if you parallel the two sections of the same tube.
So, yes i think i'd either use a FET or accept the noise of a single ECC88 triode.
Did anyone mention the nightmares of valve microphony at microvolt level?
By CCS do you mean SS CCS? As if you do your circuit won't be so pure any more. The sonic fingerprint of a SS CCS is about as obvious as that of a single FET at the input.
cheers
peter
For what it's worth here is my experience. Ok, this forum would not be worth much if we agreed upon everything
I really have no experience with modern MC transformers with nickel or amorhous cores but i have had quite a few high-end (>$1000) commercial transformers and have liked none. Yes, i understand that one may prefer the homogenised sound a transformer offers in this application on the grounds of musicality, but the reduction of perceived resolution is just too much for me.
A lowly 2sk170 with battery power and good quality passives sounds really better to me without a trace of SS hardness, glare or lack of colour. If anything some transformers contribute more solid-stateness to the sound then the fet. Would i prefer it to a similarly built ECC88 stage? Difficult question, but when dealing with less than 0.5mV the ECC88 gets a bit noisy.
Paralleling? Of course it blurs the sound even if you parallel the two sections of the same tube.
So, yes i think i'd either use a FET or accept the noise of a single ECC88 triode.
Did anyone mention the nightmares of valve microphony at microvolt level?
By CCS do you mean SS CCS? As if you do your circuit won't be so pure any more. The sonic fingerprint of a SS CCS is about as obvious as that of a single FET at the input.
cheers
peter
Hi,
Forgive me Lord for I have sinned...
Yes, Peter....it's a compromise, I know.
Trouble is I don't know of any other way to make it work and let's face it; it's just a CCD.
Without it the circuit doesn't deliver, I tried but to no avail.
Do I hear any SS nasties with it? No, honestly I don't...No stridency, no harshness whatsoever.
All it does is convert the current from the MC to a useable level for the MM stage to use...and that's the beauty of it; you can have MC inputs and MM as well.
Not easy to achieve and the MC stage is using only one coupling cap.
If we abandon MM compatibility we could try to direct couple it straight into the next amplification stage.
Re MC xformers, my experiences from the past confirm your own findings in that I never found one I liked.
Nowadays, if I had unlimited funding- which I haven't- I might give the Lundahl, S&B or Jensen a try as they're reported to be very good.
Suitable valves for headamp service are very limited but some types from former USSR may be worth looking into.
What I look for is linearity at Vg=0, which the ECC88/6DJ8 family has, high transconductance and as low a req value as I can get.
I don't know of any single triode that would meet all these requirements so paralleling triodes becomes a necessity.
IME, blurring of small signals can be avoided by careful matching of the triodes and in my case I only hear the noise levels decrease to insignificant levels when using //ed triodes.
The entire preamplier; MC headamp + phono stage doesn't hum or hiss at any normal listening level in my system even with all but the insanely low output MC cartridge.
While it may not be the most detailed system on earth, I never had the impression it was lacking any. More importantly it doesn't throw detail at you as some systems do...it's all there in a very believable, musical way.
If I where to try to improve it I would consider going for a balanced system, after all the MC cartridge is about the only source available that is truly balanced.
One could than dismiss MM compatiblity and optimise all gainstages for MC use only.
Re microphony; all stages pass the pencil test without even the slightest tendency towards microphony.
Having the MC stage running from a very low B+ surely helps in that department.
Hard to tell without knowing the operating points chosen for that stage...If you recall what valve you chose and other details I'd gladly look into it.
Cheers,
Forgive me Lord for I have sinned...
Yes, Peter....it's a compromise, I know.
Trouble is I don't know of any other way to make it work and let's face it; it's just a CCD.
Without it the circuit doesn't deliver, I tried but to no avail.
Do I hear any SS nasties with it? No, honestly I don't...No stridency, no harshness whatsoever.
All it does is convert the current from the MC to a useable level for the MM stage to use...and that's the beauty of it; you can have MC inputs and MM as well.
Not easy to achieve and the MC stage is using only one coupling cap.
If we abandon MM compatibility we could try to direct couple it straight into the next amplification stage.
Re MC xformers, my experiences from the past confirm your own findings in that I never found one I liked.
Nowadays, if I had unlimited funding- which I haven't- I might give the Lundahl, S&B or Jensen a try as they're reported to be very good.
Suitable valves for headamp service are very limited but some types from former USSR may be worth looking into.
What I look for is linearity at Vg=0, which the ECC88/6DJ8 family has, high transconductance and as low a req value as I can get.
I don't know of any single triode that would meet all these requirements so paralleling triodes becomes a necessity.
IME, blurring of small signals can be avoided by careful matching of the triodes and in my case I only hear the noise levels decrease to insignificant levels when using //ed triodes.
The entire preamplier; MC headamp + phono stage doesn't hum or hiss at any normal listening level in my system even with all but the insanely low output MC cartridge.
While it may not be the most detailed system on earth, I never had the impression it was lacking any. More importantly it doesn't throw detail at you as some systems do...it's all there in a very believable, musical way.
If I where to try to improve it I would consider going for a balanced system, after all the MC cartridge is about the only source available that is truly balanced.
One could than dismiss MM compatiblity and optimise all gainstages for MC use only.
Re microphony; all stages pass the pencil test without even the slightest tendency towards microphony.
Having the MC stage running from a very low B+ surely helps in that department.
Hard to tell without knowing the operating points chosen for that stage...If you recall what valve you chose and other details I'd gladly look into it.
Cheers,
Hi Frank,
I'm afraid my recollections are a bit hazy now. Un-viable things don't get "backed up". This was before the internet, and I had no one to compare notes with. If you think it's feasible, maybe it's worth a revisit in future.
Were you talking about a balanced phono stage a while ago? Was Benny involved?
Cheers,
I'm afraid my recollections are a bit hazy now. Un-viable things don't get "backed up". This was before the internet, and I had no one to compare notes with. If you think it's feasible, maybe it's worth a revisit in future.
Were you talking about a balanced phono stage a while ago? Was Benny involved?
Cheers,
Hi John,
It sure is...we'll wait for you to get your MC cartridge and arm.
Talking of which...have you considered giving Tom Fletcher of Nottingham Analogue a ring?
He often has second hand uni-pivot tonearms coming in from people upgrading to a more expensive model.
Plus, he's a really nice bloke to talk to who knows an awful lot about arm and TT design.
The idea of doing a completely balanced preamp ( or at least the phono part of it) is something of a love/hate affair I've been considering for ages but never got it beyond the mental state.
I haven't talked to Benny about it as yet but I just might...
Knowing Benny he'd probably opt for xformer coupling and LCR RIAA correction which would be something else worth trying.
Cheers,
It sure is...we'll wait for you to get your MC cartridge and arm.
Talking of which...have you considered giving Tom Fletcher of Nottingham Analogue a ring?
He often has second hand uni-pivot tonearms coming in from people upgrading to a more expensive model.
Plus, he's a really nice bloke to talk to who knows an awful lot about arm and TT design.
The idea of doing a completely balanced preamp ( or at least the phono part of it) is something of a love/hate affair I've been considering for ages but never got it beyond the mental state.
I haven't talked to Benny about it as yet but I just might...
Knowing Benny he'd probably opt for xformer coupling and LCR RIAA correction which would be something else worth trying.
Cheers,
drifting off topic...
Frank,
I'll keep Tom Fletcher in mind, thanks.
A fully balanced system is my goal too. Much is balanced already.
I have no quibble with transformers. To me, their benefits normally outweigh their shortfalls.
It made me laugh hearing a Flem saying the word "Bloke". My family are so stiff, they wouldn't use it, even if they knew what it meant
Cheers,
Frank,
I'll keep Tom Fletcher in mind, thanks.
A fully balanced system is my goal too. Much is balanced already.
I have no quibble with transformers. To me, their benefits normally outweigh their shortfalls.
It made me laugh hearing a Flem saying the word "Bloke". My family are so stiff, they wouldn't use it, even if they knew what it meant
Cheers,
Hey Guys,
Why balanced?
Single ended means asymmetrical distortion, ie second harmonic; musical, pleasant, not too intrusive.
Balanced means symmetrical distortion, ie third and odd order, great to look at on a CRO, but not too musical, less pleasant, noticeable.
This approach accepts that distortion is inevitable, so let's live with it.
Now, tubes.
I love tubes. Great little critters...... But, not particularly quiet.
A MC has typically 0.3mV, mercifully at a source impedance around 100R. However, magnification of such small signals obviously requires very low noise.
The 2SK170 cascoded frame grid tube is almost the optimum in this situation. This lower semiconductor device is working into the very low impedance, reciprocal of the transconductance, of the tube, no voltage amplification to speak of, so the usual issues of common source and stability don't really apply as the voltage amplifying device is a tube.
It is the poor parasitics of semis which make them sound terrible in common source/emitter. A tube offers far better voltage amplification from a musical perspective.
However, to try to do it all with tubes, and not capitalize on the noise advantages of jfets/bipolars is rather prejudiced, I feel. And Frank, a guy with your pedigree ought not to be prejudiced. (Now there's a challenge!
) And there are some things semis do so well, such as emitter followers in output stages, that to condemn them solely because they are silicon is almost silly. I don't like Harley Davidsons, either, because they affront my notions of good dynamics, particularly brakes, and refined engineering, but I can't deny that they are runaway marketing success, and there is something about riding a Harley - at least for a short time - which is quite beyond words.
Cheers,
Hugh
Why balanced?
Single ended means asymmetrical distortion, ie second harmonic; musical, pleasant, not too intrusive.
Balanced means symmetrical distortion, ie third and odd order, great to look at on a CRO, but not too musical, less pleasant, noticeable.
This approach accepts that distortion is inevitable, so let's live with it.
Now, tubes.
I love tubes. Great little critters...... But, not particularly quiet.
A MC has typically 0.3mV, mercifully at a source impedance around 100R. However, magnification of such small signals obviously requires very low noise.
The 2SK170 cascoded frame grid tube is almost the optimum in this situation. This lower semiconductor device is working into the very low impedance, reciprocal of the transconductance, of the tube, no voltage amplification to speak of, so the usual issues of common source and stability don't really apply as the voltage amplifying device is a tube.
It is the poor parasitics of semis which make them sound terrible in common source/emitter. A tube offers far better voltage amplification from a musical perspective.
However, to try to do it all with tubes, and not capitalize on the noise advantages of jfets/bipolars is rather prejudiced, I feel. And Frank, a guy with your pedigree ought not to be prejudiced. (Now there's a challenge!
) And there are some things semis do so well, such as emitter followers in output stages, that to condemn them solely because they are silicon is almost silly. I don't like Harley Davidsons, either, because they affront my notions of good dynamics, particularly brakes, and refined engineering, but I can't deny that they are runaway marketing success, and there is something about riding a Harley - at least for a short time - which is quite beyond words.Cheers,
Hugh
AKSA said:
Because I've tried both and it simply sounds better.
I run both currently; two balanced stages for the carts that have 4 individual connections, and a SE version for the Decca. They are very similar circuits.
Plus balanced there is enormous reduction of CM nasties, not exactly a worthless feature in a circuit taking 300uV and amplifying it 70dB.
I don't beleive distortion is something to live with. Every time I've reduced it, the system sounded better. To my ears the '2H is musical' argument is bollocks.
Hi,
He,he....
Well, I wasn't born prejudiced of course...and yes, doing this with valves was a challenge too.
As for noise well if we take the low noise E188CC with a Raeq of 250 Ohm and divide that by a factor of 4, we have 62.5 Ohm of Johnson noise.
I can't hear any noise in my system.
What I do hear though is a noisy BF244A which I use as a CCS, so these need careful selection as well...nothing ever comes easy.
Mind you, I'm really prejudiced when it comes to cars and bikes...
While I like the looks of a Ferrari, I would never buy one.
I respect a Harley Davidson but would rather be the proud owner of an old Norton...even if it means carrying a toolbox with me to stop it from leaking oil all over the place.
Cheers fellows,
He,he....
Well, I wasn't born prejudiced of course...and yes, doing this with valves was a challenge too.
As for noise well if we take the low noise E188CC with a Raeq of 250 Ohm and divide that by a factor of 4, we have 62.5 Ohm of Johnson noise.
I can't hear any noise in my system.
What I do hear though is a noisy BF244A which I use as a CCS, so these need careful selection as well...nothing ever comes easy.
Mind you, I'm really prejudiced when it comes to cars and bikes...
While I like the looks of a Ferrari, I would never buy one.
I respect a Harley Davidson but would rather be the proud owner of an old Norton...even if it means carrying a toolbox with me to stop it from leaking oil all over the place.
Cheers fellows,
Why balance?
Hi,
For me it is part of my pedigree. I've spent more time in broadcast and production where all interconnects are balanced. They need to be, to cope with the noisy environment.
Well, I've found benefits at home too. Home is becoming a more noisy environment as time goes on.
Why balance the preamp?
Unbalancing and rebalancing cause problems IMO.
I agree with unbalanced for driving speakers, however. This is where most distortion occurs, and I'd rather have a balanced spectrum of low order odd and even harmonics.
Not everyones taste, I agree...
Cheers,
Hi,
For me it is part of my pedigree. I've spent more time in broadcast and production where all interconnects are balanced. They need to be, to cope with the noisy environment.
Well, I've found benefits at home too. Home is becoming a more noisy environment as time goes on.
Why balance the preamp?
Unbalancing and rebalancing cause problems IMO.
I agree with unbalanced for driving speakers, however. This is where most distortion occurs, and I'd rather have a balanced spectrum of low order odd and even harmonics.
Not everyones taste, I agree...
Cheers,
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