Samuel Jayaraj said:
I would be interested in comparing the JLH to GEM, given their obivious linkage. I was a little surprised at the low bass "punch" as all of my jlh (1969s) produce bass very well, and since the gem works like a jlh at low output levels, it should have retained that attribute.
what makes an amp punch here and there is knowledge which
is based in hidden art, only a few could see such a hidden
knowledge in an amp
is based in hidden art, only a few could see such a hidden
knowledge in an amp
To add to the list in my previous post:
15. Replace the 2 Amp Fast Blow fuses with the recommended rating types before playing very loud music.
16. If you are driving the GEM into a capacitive load, use 0.22E 5/10 Watt resistor in the speaker signal wire.
When I say that the Bass punch is not the best, it is in comparison to the very best there is. I am not sure whether it is an issue with the rise time of the amp or the very low input impedance that is causing a troublesome load to the signal source. As already mentioned "a low output impedance preamp with adequate voltage swing will certainly boost the performance in this area. A reasonably desirable preamp should be a Class A solid state with output impedance lesser than 10E. A very good valve preamp should also perform well".
I do not have a JLH and I don't plan to immediately make one either. But given the superlatives of the JLH as I have read on many sites including Geoff's, I would expect the Bass of the JLH to be on the lines of the GEM - 'very tuneful but not authoritative as you hear on the Stochino amp or some of the IGBT output stage amps that I have heard from Forte'. I guess there are many bipolar amps, especially those with multiple output devices that also appear to produce a lot of 'punchy' bass but too many times the bass is a bit 'lumpy' and not detailed. I think the AKSA scores very well in this department, having made a clone myself just out of curiosity. Mike B's amp that is doing the rounds in the other thread on this forum, I suspect is also a great performer in the Bass region.
The slam of the GEM is very identical to what you can get out of an LM3886 chip - very much there but losing out in terms of the ultimate punch + detail/resolution that is stunning.
Does anybody have any idea on improving low level resolution and operating the Voltage Section off a higher voltage?
Graham and Carlos, where are you guys? We need you here!!
15. Replace the 2 Amp Fast Blow fuses with the recommended rating types before playing very loud music.
16. If you are driving the GEM into a capacitive load, use 0.22E 5/10 Watt resistor in the speaker signal wire.
When I say that the Bass punch is not the best, it is in comparison to the very best there is. I am not sure whether it is an issue with the rise time of the amp or the very low input impedance that is causing a troublesome load to the signal source. As already mentioned "a low output impedance preamp with adequate voltage swing will certainly boost the performance in this area. A reasonably desirable preamp should be a Class A solid state with output impedance lesser than 10E. A very good valve preamp should also perform well".
I do not have a JLH and I don't plan to immediately make one either. But given the superlatives of the JLH as I have read on many sites including Geoff's, I would expect the Bass of the JLH to be on the lines of the GEM - 'very tuneful but not authoritative as you hear on the Stochino amp or some of the IGBT output stage amps that I have heard from Forte'. I guess there are many bipolar amps, especially those with multiple output devices that also appear to produce a lot of 'punchy' bass but too many times the bass is a bit 'lumpy' and not detailed. I think the AKSA scores very well in this department, having made a clone myself just out of curiosity. Mike B's amp that is doing the rounds in the other thread on this forum, I suspect is also a great performer in the Bass region.
The slam of the GEM is very identical to what you can get out of an LM3886 chip - very much there but losing out in terms of the ultimate punch + detail/resolution that is stunning.
Does anybody have any idea on improving low level resolution and operating the Voltage Section off a higher voltage?
Graham and Carlos, where are you guys? We need you here!!
Hi all;
Having built a couple of Gems hopefully justify remarks.
The real diamond and / or Gem is Graham Maynard, a true genius in our times!. If ever we could prevent not honoring past greats then all priveleged to have built the Gem owe him some reward for his master genius.
Words cannot describe the joy having built his design.
Is there any way we can establish some form of trust to honor such a person? I'll gladly participate.
Keep the passion!
Daniel
Having built a couple of Gems hopefully justify remarks.
The real diamond and / or Gem is Graham Maynard, a true genius in our times!. If ever we could prevent not honoring past greats then all priveleged to have built the Gem owe him some reward for his master genius.
Words cannot describe the joy having built his design.
Is there any way we can establish some form of trust to honor such a person? I'll gladly participate.
Keep the passion!
Daniel
i tried over private mail....i am affraid that that ain't gonna happen.....DX and Mr. Graham are lost to this thread unfortunately.... i don't blame anybody.... it is very unfortunate for all of us..... oh well.....
Despite of that...."everybody loves Sunrise"
I love Sunrise too...also sunset.
Those things, problems, are a matter of time only.
My computer is bad...direct mails are beeing lost...enormous confusion here.
regards,
Carlos
I love Sunrise too...also sunset.
Those things, problems, are a matter of time only.
My computer is bad...direct mails are beeing lost...enormous confusion here.
regards,
Carlos
Yes, yes baad computer 😀
nice to see you Carlos.... they say that time heals everything....
i will send You an email to Your private mail just as You have asked to do if someone here needs an advice.....
sunny
nice to see you Carlos.... they say that time heals everything....
i will send You an email to Your private mail just as You have asked to do if someone here needs an advice.....
sunny
I'm sad that Carlos and Graham have been offended enough to leave the thread. There are those out there who would deride others ideas on technical point scoring for what gain? I have built many amps and heard so many technical stories; but did the amps rate the listening; no they didn't. I have the misfortune of being a well qualified tech type and still not knowing what sounds good unless I listen to it. i have nothing but praise for those who are so passionate that they will build and destroy many designs in order to achieve their best. Isn't this such a gift to the DIY forum? So why offend? Do you really know any better? What have you to offer that's new, innovative and sounds great? Yes only silence and critic...
what a prize!
what a prize!
Samuel Jayaraj said:
I always thought that this "stunning" ultimate punch only available with mosfet output. When building the GEM, I was sad because I have to have a BJT amp for a reference 😀 But thank's to Samuel, I'm building the Stochino, and am happy to see that it uses mosfet, one of my favourite mosfets 😉
I made formal invitation to Graham return...as now forum is better.
Let's see if will succed or not.
We can loose all the battles needed...not to win the war...but to reach the peace.
regards,
Carlos
Let's see if will succed or not.
We can loose all the battles needed...not to win the war...but to reach the peace.
regards,
Carlos
I have sent Graham a private email requesting him not to perceive blunt statements as personal attach and thereby even have sufficient grounds to back in the forum for the furtherance of the GEM amplifier.
Carlos, is back I suppose?!
Carlos, is back I suppose?!
Absolutely Kambule, I've been quitely following this thread, checking in on it each day in the hope that has come to life again. It is a real shame what has happened and that this design may never reach its full potential.
Graham, I hope you can find it in yourself to ignore those who are careless with their words and re-engage with this thread at some point in the future. I suspect there are a lot of people hoping for it.
Grant.
Graham, I hope you can find it in yourself to ignore those who are careless with their words and re-engage with this thread at some point in the future. I suspect there are a lot of people hoping for it.
Grant.
Carlos remains with us, fortunately.
Graham was very angry with perceived insults and aggression, and has left permanently. This forum survives and feeds off its clever contributors, and manners, respect and a pleasant approach is mandatory.
Most people are here to learn something, so the gems are really worth gracious and welcoming behaviour.
There are lots of lesser forums where abuse, aggression and offensive behaviour is the norm; perhaps people so inclined should gravitate elsewhere.
Cheers,
Hugh
Graham was very angry with perceived insults and aggression, and has left permanently. This forum survives and feeds off its clever contributors, and manners, respect and a pleasant approach is mandatory.
Most people are here to learn something, so the gems are really worth gracious and welcoming behaviour.
There are lots of lesser forums where abuse, aggression and offensive behaviour is the norm; perhaps people so inclined should gravitate elsewhere.
Cheers,
Hugh
That would be nice Hugh. But I think they need a gentle push from the mods. Children need to know there limits.
I am in full agreement with you as far as the quality of the board. And as long as we can remain respectful of others we can keep the pool of talent we have.
-Chris
I am in full agreement with you as far as the quality of the board. And as long as we can remain respectful of others we can keep the pool of talent we have.
-Chris
Graham may "never" come back
I had a few personal mail exchanges with Graham. Initially he assumed that I disguised myself as tlf9999 and attacked him. After I clarified that I was one of the few people on this forum who use my real name as id and so on, he did not seem convinced but was questioning as to why I had apologised; I had made myself very clear that tlf9999 did make some very valid statements that might have seemed forthright and blunt, and the thread took this turn at the instance of my version of the GEM having oscillation problems without miller cap, which is why I felt bad and apologised for the turn of events and his 'misplaced perceptions'. He simply does not want to understand my point.
He curtly states that the GEM needs no further improvement. However, he did indicate that he had thought about using a regulated supply for the front end and increasing Re to 0R47 ohms.
To cut the details short, Graham Maynard is definitely going through a phase when he feels that all the world is against him; I opt not to use technically correct words to describe this phenomenon.
In the face of this, I doubt that the GEM's performance can be further heightened without more participation/recommendations from those who are more technically competent here.
Much of the attention has deservedly turned to Mike's AssymSym 5.2 amp.
So has the GEM died a natural death or is there any hope left?
I had a few personal mail exchanges with Graham. Initially he assumed that I disguised myself as tlf9999 and attacked him. After I clarified that I was one of the few people on this forum who use my real name as id and so on, he did not seem convinced but was questioning as to why I had apologised; I had made myself very clear that tlf9999 did make some very valid statements that might have seemed forthright and blunt, and the thread took this turn at the instance of my version of the GEM having oscillation problems without miller cap, which is why I felt bad and apologised for the turn of events and his 'misplaced perceptions'. He simply does not want to understand my point.
He curtly states that the GEM needs no further improvement. However, he did indicate that he had thought about using a regulated supply for the front end and increasing Re to 0R47 ohms.
To cut the details short, Graham Maynard is definitely going through a phase when he feels that all the world is against him; I opt not to use technically correct words to describe this phenomenon.
In the face of this, I doubt that the GEM's performance can be further heightened without more participation/recommendations from those who are more technically competent here.
Much of the attention has deservedly turned to Mike's AssymSym 5.2 amp.
So has the GEM died a natural death or is there any hope left?
Negative Sam, there are many people constructing it, and having conversations with
Graham, and i am receiving a copy of the conversations he is having, when the guys accepted to let him forward to me.
There are two guys that do not want the forward....asking for confidential conversations.
The thread explain many times that, depending the construction, the wires size and the boards, that it may oscilate, and that Miller capacitor may be needed in those cases.
Also we know that oscilating circuits do not reproduce quality.
So, despite your intelligent evaluations, that contribute a lot, there are people that, alike you, have preserved the respect related Graham and the confidence on his work and on my words, that was confirmed in Michael's thread....where i said that Symassym is very good.....and confirmed by many guys!.
Also, i am telling once again.
GEM is a precious stone, a Diamond amplifier, that well constructed will make everyone happy.
Well...even everyone can have one or two exceptions, as i cannot believe that can be nice to whole world...this is too much, even for those wonderfull amplifiers.
May be the ones that did not like it...no problem....majority, will apreciate it, because it is really nice!
regards,
Carlos
Graham, and i am receiving a copy of the conversations he is having, when the guys accepted to let him forward to me.
There are two guys that do not want the forward....asking for confidential conversations.
The thread explain many times that, depending the construction, the wires size and the boards, that it may oscilate, and that Miller capacitor may be needed in those cases.
Also we know that oscilating circuits do not reproduce quality.
So, despite your intelligent evaluations, that contribute a lot, there are people that, alike you, have preserved the respect related Graham and the confidence on his work and on my words, that was confirmed in Michael's thread....where i said that Symassym is very good.....and confirmed by many guys!.
Also, i am telling once again.
GEM is a precious stone, a Diamond amplifier, that well constructed will make everyone happy.
Well...even everyone can have one or two exceptions, as i cannot believe that can be nice to whole world...this is too much, even for those wonderfull amplifiers.
May be the ones that did not like it...no problem....majority, will apreciate it, because it is really nice!
regards,
Carlos
Carlos, with due respect to you and your superb intentions, you have gone through this before - with regard to Mike's amp, maintaining that Pavel's initial discovery of denigration of sound due to oscillation when using the latest Toshiba devices is a non-issue since your version did not oscillate, till everyone came around to appreciate the discovery and eventual solution which now has led to a very fine amplifier that lends itself to public verifiability.
All I am saying is that the GEM has not evolved fully to the point of 100% public verifiability as no official PCB has been published which incorporates all amp circuitry devices on a single board.
In the GEM thread, I have given my personal evaluation of the sonic excellence of the GEM vs. the Stochino amp. Note that upto date, even the few who have constructed the GEM successfully have not commented or contested my evaluation. Hence, it follows that as I write atleast, my opinion that the GEM needs improvement, is valid.
My only quest was, are there any takers?
It is much the same question that Hugh has posed in as far as Mike's amp is concerned.
All I am saying is that the GEM has not evolved fully to the point of 100% public verifiability as no official PCB has been published which incorporates all amp circuitry devices on a single board.
In the GEM thread, I have given my personal evaluation of the sonic excellence of the GEM vs. the Stochino amp. Note that upto date, even the few who have constructed the GEM successfully have not commented or contested my evaluation. Hence, it follows that as I write atleast, my opinion that the GEM needs improvement, is valid.
My only quest was, are there any takers?
It is much the same question that Hugh has posed in as far as Mike's amp is concerned.
Of course Samuel, this is fair to check your evaluation and to research into the
very best possible related your needs.
I suppose Graham is already satisfied, and he finished his researches, considering good enougth to publish, and to be his main amplifier, his partner to enjoy moments of pleasure listening.
But you can ask people their ideas, also you can progress making another sample, with some modifications that may increase something related your ideas, tastes, meterings and references.
So, be confortable to take the Whell drive of this thread, and alike a ship, conduct it to another new horizon.
He gave up....i also entered to avoid misunderstandings, to inform that there are people that construct, and Dragon2 posted his evaluation, and there are others that are doing in contact with Graham.
Others that constructed Symassym, are preparing themselves to construct GEM too, and some already started.
As thread is without the designer, people are not bothering to came here to publish partial constructions or comments, as Graham are not reading the thread anymore...so....messages are going to him, and some messages arrive my mail box too.
When developing the amplifier, and i was doing with him, following Graham's steps, in some moment we said one to the other...it is so nice, that if we try to make it better, it may turn worst, as may had already find it's peak of performance....he decided to stop there...officially, GEM finished there.
But, of course, the circuit is now in "public"...openned wide world, and you can produce GEM revisited.....GEM reduced....GEM expanded....GEM, another aproach....and this may be good for all.
Related to me, and i suppose that Graham will agree with that, you are welcome to do whatever you want, to contribute with our forum brothers.
Related Graham, the best he may need, for a while, is to be free of computer to enjoy his music, his lovely wife and take care of his family...he already gave his contribution to many guys that are listening his products, not only published in our wonderfull forum, but also in some also wonderfull magazines.
Related yourself Samuel, already beeing very satisfied with your amplifier, you may not have the need to bother yourself making GEM sound the same...as you will have no advantage...will still having something that is the maximum, top quality, in your mind...better is to discover something that turn you "on".... and them, to modify your actual amplifier to give another more interesting sonic quality to your ears..... because adjust GEM to match your "reference" unit...will produce two reference units....the same thing may be boering to you.... do not know, this is your decision.
It is possible, that Graham's recognition as beeing a pionner in certain aspects, and very conservative in others, will happen in future, alike JLH, already respected and more than 45 years passed since he decided to replace his Williamson Tube design by something Solid State.... Graham centered his researches to obtain something more related JLH, beeing GEM, something based in JLH philosophie.... the main idea is there!....if he win JLH in some aspects, if he loose in some other, we will see in the future, when no one that had any kind of connection with him, produce evalutions in the distant future.
GEM is a precious stone, and i think alike the stone, it will survive and will be there for long time.
regards,
Carlos
very best possible related your needs.
I suppose Graham is already satisfied, and he finished his researches, considering good enougth to publish, and to be his main amplifier, his partner to enjoy moments of pleasure listening.
But you can ask people their ideas, also you can progress making another sample, with some modifications that may increase something related your ideas, tastes, meterings and references.
So, be confortable to take the Whell drive of this thread, and alike a ship, conduct it to another new horizon.
He gave up....i also entered to avoid misunderstandings, to inform that there are people that construct, and Dragon2 posted his evaluation, and there are others that are doing in contact with Graham.
Others that constructed Symassym, are preparing themselves to construct GEM too, and some already started.
As thread is without the designer, people are not bothering to came here to publish partial constructions or comments, as Graham are not reading the thread anymore...so....messages are going to him, and some messages arrive my mail box too.
When developing the amplifier, and i was doing with him, following Graham's steps, in some moment we said one to the other...it is so nice, that if we try to make it better, it may turn worst, as may had already find it's peak of performance....he decided to stop there...officially, GEM finished there.
But, of course, the circuit is now in "public"...openned wide world, and you can produce GEM revisited.....GEM reduced....GEM expanded....GEM, another aproach....and this may be good for all.
Related to me, and i suppose that Graham will agree with that, you are welcome to do whatever you want, to contribute with our forum brothers.
Related Graham, the best he may need, for a while, is to be free of computer to enjoy his music, his lovely wife and take care of his family...he already gave his contribution to many guys that are listening his products, not only published in our wonderfull forum, but also in some also wonderfull magazines.
Related yourself Samuel, already beeing very satisfied with your amplifier, you may not have the need to bother yourself making GEM sound the same...as you will have no advantage...will still having something that is the maximum, top quality, in your mind...better is to discover something that turn you "on".... and them, to modify your actual amplifier to give another more interesting sonic quality to your ears..... because adjust GEM to match your "reference" unit...will produce two reference units....the same thing may be boering to you.... do not know, this is your decision.
It is possible, that Graham's recognition as beeing a pionner in certain aspects, and very conservative in others, will happen in future, alike JLH, already respected and more than 45 years passed since he decided to replace his Williamson Tube design by something Solid State.... Graham centered his researches to obtain something more related JLH, beeing GEM, something based in JLH philosophie.... the main idea is there!....if he win JLH in some aspects, if he loose in some other, we will see in the future, when no one that had any kind of connection with him, produce evalutions in the distant future.
GEM is a precious stone, and i think alike the stone, it will survive and will be there for long time.
regards,
Carlos
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