fdegrove said:
If you have doubts, you should first contact the parties who have commercila interests. If they don't mind who else can?
Me personally (although I know it doesn't apply to me) have no problem with any sort of those things.
fdegrove said:
Frank,
If you are worried about stepping on Joe's toes, why don't you email him and ask...
My guess is that you won't. Sprinkled thru-out this thread are enuff clues, et all, that Joe has told us pretty much what the difference is between his commercial product & his DIY offering -- any competent designer (not me) could come up with his own flavour of Joe's commercial product. The big trick up Joe's sleeve is how he can sell it so cheap -- and Joe has been in the biz long enuff i'm sure he know's what he is doing.
If you have a circuit that was shown you by a designer and he asked you to keep it private -- that we don't want to know, either here or in private mail.
dave
I would defently be interrested to learn more about this stuff!
So Frank if you bring it on it will be very much appriciated!!🙂
Tor Martin🙂
So Frank if you bring it on it will be very much appriciated!!🙂
Tor Martin🙂
Hi,
Uh,Oh....what's going on? Did I single handledly bring you all to a halt?
Surely that wasn't my intention.
No other guys have tube knowledge and chip knowledge here except Moamps?
That surprises me a little.
I will.
Well, I assume you know what Joe referred to, as do I...still there are steps inbetween that could be discussed and would likely improve on the original CF.
Well, most of what I'll propose won't come cheap, yet I feel it'll be money well spent.
Some of you know me well enough to know Frank's no bean counter...the trick is to spend money where it matters most, I reckon?
No, no that's not the case...if it were, I'd kept my mouth shut in the first place.
So, what can we do but present a number of incarnations of CFs?
Not much really, except for the fact that not all CFs are born equal and that attention to detail and PS usually pays off...in the end I'm afraid we'll be pushing the GC close to its' seams as well
since there's no point developing one end while ignoring the other.
Any suggestions are most welcome...I don't want this to be a one man show but rather an interactive development as it befits a DIY forum.
\\Excuse the long rant...hope you had the necessary attention span.
Cheers,😉
Uh,Oh....what's going on? Did I single handledly bring you all to a halt?
Surely that wasn't my intention.
No other guys have tube knowledge and chip knowledge here except Moamps?
That surprises me a little.
I will.
Well, I assume you know what Joe referred to, as do I...still there are steps inbetween that could be discussed and would likely improve on the original CF.
Well, most of what I'll propose won't come cheap, yet I feel it'll be money well spent.
Some of you know me well enough to know Frank's no bean counter...the trick is to spend money where it matters most, I reckon?
No, no that's not the case...if it were, I'd kept my mouth shut in the first place.
So, what can we do but present a number of incarnations of CFs?
Not much really, except for the fact that not all CFs are born equal and that attention to detail and PS usually pays off...in the end I'm afraid we'll be pushing the GC close to its' seams as well
since there's no point developing one end while ignoring the other.
Any suggestions are most welcome...I don't want this to be a one man show but rather an interactive development as it befits a DIY forum.
\\Excuse the long rant...hope you had the necessary attention span.
Cheers,😉
planet10 said:
Hi Guys,
Just want to reinforce what Dave has said above.
Go hear the beginning of this thread (Post #2) and you will a rather more complex tube buffer, as used in the JLTi. No values are shown, but if you want to have a go... don't see what I can do about, BUT if you were going develop a commercial product based on that, then, at the very least you'd be infringing Copyright.
As Dave points out, and indeed I've referred to it, the tube buffer rails are SuperReg'd - this is a Constant Current Class A regulator with typically 120dB PS rejection ratio.
Do these differences improve the sound... what you think?
Yet by keeping these elements simpler, such as a decent CF and reasonable power supply (moamps out-did my recommendation and got it right), then the results are still gratifying.
The big one I did pass on is the 'LPF' trick on the input of the 3875. That has been left fully intact as used in the JLTi. When I told Allen Wright what it did to the soundstage, he immediately said 'Slew Rate' - and it is the buffer that makes it possible to implement (no pot here). I could hardly leave it out, it would waste so much of the potential of the CF. Ask Pedja about it. Even when using a fet buffer, the LPF makes a big difference!
The bottom line here is DIY - that means you are doing it for YOURSELF, so IF you want to cross that line, it behooves to do the right thing, as indeed I would.
Joe R.
PS: Sorry if this sounds a bit too preachy.
fdegrove said:
Don't! It's OK.
It may well be, but others will be a judge of that. 😉
fdegrove said:
OK, we have a simple CF, we also had (see Post #2) SuperLinear Cathode Follower, now if you can better that, I'd be mighty interested.
Re pushing the GC too close to its seams, you may be surprised, as indeed I was. The SLCF is as good as I know of anything that is a unity gain stage (the SLCF in the JLTi can be improved upon even yet - with marginal improvement). The 3875, once slew rate limited (passive) is quite amazing.
My reference amps are worth A$35.000 - that's an RTP Preamp and a pair of mono-block Isolated Loop Amplifier (when Allen comes out with his Tube Power Amp CookBook there will be a chapter on this radical new power amp concept - a push-pull amplifier that process a single signal in a constantly continuous loop as the power supply bounces the signal back into the circuit - and effectively no centre-tap on the primary). This is pure SOTA.
Just how does the JLTi stack up? As hugely inferior? Absolutely not. Is it as good, no! But it is so good that I can switch from the 'reference amps' to the JLTi in front of a room of critical people (including, yes, Terry and Allen Wright - Sunday night), and everyone in the room agreeing: "Hey, this little amp really does play music! Nobody said: "Get this thing out of here!" I asked several if they considered it high-end and no doubt they did. I consider it a minor little miracle and I know of no better way of getting a real high-end sounding amplifier for decent amount of dollars! It won't be embarrased in any company... if done just right!
OK, it's in your court now!
Joe R.
I would like more of your thoughts on removing the R/C snubber and R/L low pass Network on Your Output stages Thanks in advance.Kuei Yang Wang said:
Hi Joe,
The idea, as I had it in mind was to present some variation on a theme wandering between the bipolar CF as you gracefully presented in all its elegance, without going to the summit of CFs which quite likely is the SLCF.
The fact that Allen and probably yourself as well, have developed the SLCF is reason enough for me not to present it and the reason why I'd have e-mailed you in the first place.
I have a lot of respect for intelectual property so I'd only presented some more generic design possibilities.
I did say close to, not too close.😉
There are of course the laws of diminishing returns which I don't really care about from a DIY POV.
Anyway, thank you for the green light... 😎
I don't intend to build anything myself just show some alternative inroads as far as the CF + PSU goes and if there's any interest, just help our members replying to some of their QQ if needed.
Cheers,😉
The idea, as I had it in mind was to present some variation on a theme wandering between the bipolar CF as you gracefully presented in all its elegance, without going to the summit of CFs which quite likely is the SLCF.
The fact that Allen and probably yourself as well, have developed the SLCF is reason enough for me not to present it and the reason why I'd have e-mailed you in the first place.
I have a lot of respect for intelectual property so I'd only presented some more generic design possibilities.
I did say close to, not too close.😉
There are of course the laws of diminishing returns which I don't really care about from a DIY POV.
Anyway, thank you for the green light... 😎
I don't intend to build anything myself just show some alternative inroads as far as the CF + PSU goes and if there's any interest, just help our members replying to some of their QQ if needed.
Cheers,😉
I'm not naive enough to think that potential manufacturers don't come and look around these forums but generally speaking, I think that it is safe to say there are those who will go the DIY route (for their own use) and those that want to go out and spend big money, and extremely few who have a foot in both camps!
I doubt those with no interest (or ability) in DIY hi-fi will even know about these forums. In other words, any potential customers for the Jlti are not going to say 'hang on somebody is going to show us how to build one of these so we won't buy one'.
I doubt those with no interest (or ability) in DIY hi-fi will even know about these forums. In other words, any potential customers for the Jlti are not going to say 'hang on somebody is going to show us how to build one of these so we won't buy one'.
fdegrove said:
Respect leads to self-respect - old proverb? Should be.
OK - may I just say that to fit into the established theme, it should be unity gain?
That way we can compare like with like.
As for PSU - go for it.
Joe R.
Nuuk said:
I was thinking much along the same lines myself. But that is not all:
Consider this: I was first alerted to the whole GC thing, not just because I knew of Thorsten (I did) but because someone approached me with the idea of building a Thorsten IGC. He did not have the experience/ability to construct himself. I must say I was not that enamored by the idea... chip power amps? You've gotta be kidding.
The point I'm making is this, this guy never constributed to any DIY forums, neither did any of his friends.
But they were sure reading them!!!!!!!
Don't think that we are only ones seeing these postings. There are a lot out there who like reading and taking it all in. I wonder why so many people just love reading DIY magazines? A lot! It's a fascination with them. Like other people like reading about cars they cannot ever afford. At least we are discussing something affordable.
Joe R.
Hi Joe,
Aren't all CFs unity gain? I mean the "better " ones approach unity, most swing between .95 and .98 I think?
Anyway, I see your point so no probs and when I'm ready I'll start a new thread on it which seems the best policy.
I you check the forums' homepage you'll see the number of logged in members and the guests at the bottom of the page.
Quite often the guests outnumber the members by a considerable margin.
Cheers, 😉
Aren't all CFs unity gain? I mean the "better " ones approach unity, most swing between .95 and .98 I think?
Anyway, I see your point so no probs and when I'm ready I'll start a new thread on it which seems the best policy.
I you check the forums' homepage you'll see the number of logged in members and the guests at the bottom of the page.
Quite often the guests outnumber the members by a considerable margin.
Cheers, 😉
I don't mind it being here as it will fit into the topic of unity gain buffer with subsequent bandwidth limited IGC. Like your suggested CF or whatever (& PSU), Lo-Z output. If you wish to present a different IGC, then maybe... I will leave that up to you.
Quite right.
Joe R.
Hi!
I thought I got this brilliant idea:
The grid bias voltage in my buffer was a little to high, 4 V and I didn`t have any smaller resistors to play around with. So I thought why don`t I make a constant voltage source, something like a battery.🙂 I had a couple of tl431 laying around, so I replaced the 10k resistors with one tl431 arranged with anode to ground and ref to cathode and bypassed it with a 47uF capasitor. I thought this would give a low noise, constant 2.5 v dc for bias and would be better than a resistor even if the resistor was bypassed by a capasitor.
But I was wrong, because now I get no sound at all!
But the bias voltage is fine.
Can anybody explain why this didn`t work?
Maybe I have to use one regulator pr cathode or will this not work at all with cathode followers (only "anode followers")?😕
Tor Martin
🙂
I thought I got this brilliant idea:
The grid bias voltage in my buffer was a little to high, 4 V and I didn`t have any smaller resistors to play around with. So I thought why don`t I make a constant voltage source, something like a battery.🙂 I had a couple of tl431 laying around, so I replaced the 10k resistors with one tl431 arranged with anode to ground and ref to cathode and bypassed it with a 47uF capasitor. I thought this would give a low noise, constant 2.5 v dc for bias and would be better than a resistor even if the resistor was bypassed by a capasitor.
But I was wrong, because now I get no sound at all!
But the bias voltage is fine.Can anybody explain why this didn`t work?
Maybe I have to use one regulator pr cathode or will this not work at all with cathode followers (only "anode followers")?😕
Tor Martin
🙂
the tube buffer - 6922 @ 24V??
Getting back a little here, I remember Joe R. speaking about seeing a circuit with a 6Dj8 working with 24 volts. I thought that was on the low side but.... I don't know if this is it but heres a tube buffer with + / 24V.
http://www.diyzone.net/diy/references/tube/6dj8buffer_2.htm
Getting back a little here, I remember Joe R. speaking about seeing a circuit with a 6Dj8 working with 24 volts. I thought that was on the low side but.... I don't know if this is it but heres a tube buffer with + / 24V.
http://www.diyzone.net/diy/references/tube/6dj8buffer_2.htm
Member
Joined 2002
Every time i look at this web-page i spend hours on it looking and browsing. i wish i could read it in english. maybe order some stuff from them there boards look awesome. http://www.diyzone.net
Hi,
Yup..and I'm not sure about the chicken egg relation as far as buffered IGCs go...
Suffice it to say that the 6DJ8 is linear at Vg 0 and Vp 24VDC...
as a CF this is not what I'd call great.
Add a CCS in the tail and things start to look a lot better.
Up the voltages and current through the tube, use a CCS and you're closer to home, IME.
Cheers,😉
Yup..and I'm not sure about the chicken egg relation as far as buffered IGCs go...
Suffice it to say that the 6DJ8 is linear at Vg 0 and Vp 24VDC...
as a CF this is not what I'd call great.
Add a CCS in the tail and things start to look a lot better.
Up the voltages and current through the tube, use a CCS and you're closer to home, IME.
Cheers,😉
Hi,
maybe is ECC86 better choice for low PS (24V).(like ULTRAPATH from Welborne Labs).
Did someone noticed tube buffered LM1875 (simple delayed start and DC protect ciricuit) on this site and date of publishing (one year ago)?
Regards
maybe is ECC86 better choice for low PS (24V).(like ULTRAPATH from Welborne Labs).
Did someone noticed tube buffered LM1875 (simple delayed start and DC protect ciricuit) on this site and date of publishing (one year ago)?
Regards
Hi,
Work it will.
I'm afraid you're missing the point though...In order to have some dynamic headroom voltages should go up, not down.
Oh, and when working with tubes, curves are very handy indicators...if you know how to read them.
Sorry, again there no such thing as a free lunch...
Cheers,😉
Work it will.
I'm afraid you're missing the point though...In order to have some dynamic headroom voltages should go up, not down.
Oh, and when working with tubes, curves are very handy indicators...if you know how to read them.
Sorry, again there no such thing as a free lunch...
Cheers,😉
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