> with none of the detrimental effects of feedback loops.
Where did that quote come from ?
It wasn't from me.
Having said that, I do like the sound of those amps I built without global feedback loop.
But that is all subjective.
You have a recent one yourself -- the balanced phono.
Cheers,
Patrick
Where did that quote come from ?
It wasn't from me.
Having said that, I do like the sound of those amps I built without global feedback loop.
But that is all subjective.
You have a recent one yourself -- the balanced phono.
Cheers,
Patrick
From their abstract, I don't mind but saying that in the wrong crowd will earn you some brickbats.
Finally got some time to do some testing and listening after being away.
First tested were the regulators.
They are about 3x quieter than a 317_337 regulator, but still some way from the likes of LT3045.
Peak-to-peak noise is less than 15µV.
So I decided to block off the DC and listened to the regulator output directly with a sensitive in-ear phone.
Dead quiet, better than I expected.
Then the amp itself.
The regulator slow-start and the servo are both very slow (deliberately so) and takes some 10 seconds to settle fully.
The start-up transients can be higher than the SHPP trigger level, especially if the regulators are not well matched.
The simple work-around is to leave out the latching option of the SHPP.
The relay will then only turn on when the DC level is lower than the SHPP trigger level.
In my case +/-90mV.
It is absolutely essential that you use the SHPP, unless you can be sure that the power rails start up simultaneously.
(That is the case for the Silent Switcher as used by cwtim01.)
Then it's time for music.
As cwtim01 already said, the sound is very neutral and natural.
It is a very fast amp but with tight bass at the same time.
On good recordings, it really sings and keeps you wanting to listen for hours.
On poor recordings, it reveals all the defects with total clarity.
So despite the poor PSRR of the circuit, I am pleasantly surprised by how nice it turns out.
Time to send it off for an independent audition next week.
Patrick
First tested were the regulators.
They are about 3x quieter than a 317_337 regulator, but still some way from the likes of LT3045.
Peak-to-peak noise is less than 15µV.
So I decided to block off the DC and listened to the regulator output directly with a sensitive in-ear phone.
Dead quiet, better than I expected.
Then the amp itself.
The regulator slow-start and the servo are both very slow (deliberately so) and takes some 10 seconds to settle fully.
The start-up transients can be higher than the SHPP trigger level, especially if the regulators are not well matched.
The simple work-around is to leave out the latching option of the SHPP.
The relay will then only turn on when the DC level is lower than the SHPP trigger level.
In my case +/-90mV.
It is absolutely essential that you use the SHPP, unless you can be sure that the power rails start up simultaneously.
(That is the case for the Silent Switcher as used by cwtim01.)
Then it's time for music.
As cwtim01 already said, the sound is very neutral and natural.
It is a very fast amp but with tight bass at the same time.
On good recordings, it really sings and keeps you wanting to listen for hours.
On poor recordings, it reveals all the defects with total clarity.
So despite the poor PSRR of the circuit, I am pleasantly surprised by how nice it turns out.
Time to send it off for an independent audition next week.
Patrick
Oh man what a stupid mistake. My 2SA1312 are BL grade so I need to place a new order. Thanks anyway for pointing it out. So if somebody needs 2SC3324GR, I'm more than happy to sell them...
Incidentally I specified 2SK209GR only because BL grade is not stock at Digikey or Mouser.
If you can find BL, by all means use them.
But be careful you are quite close to or exceed the max. power limit at max. Idss.
Most of the GR grade I have (from Mouser) are around 5mA Idss, more than enough for this purpose.
Patrick
If you can find BL, by all means use them.
But be careful you are quite close to or exceed the max. power limit at max. Idss.
Most of the GR grade I have (from Mouser) are around 5mA Idss, more than enough for this purpose.
Patrick
As Patrick hinted I was given the opportunity to audition the Pioneer Super Linear Circuit at my place,
and in comparison to the F5 HA and the DAO that I built during the last two years and that serve as my
benchmark headphone amplifiers since.
I have a bit of a journey behind me during the last 13 years with a good dozen headphone
amplifiers built, with various topologies from tubes over hybrid to solid state. The few that have
found my homepage might know that I was quite sceptical years ago about solid state amplifiers,
finding them sounding too cold and sterile for my taste...
Well this has changed after I got in contact with EUVL and after I heard his prototype DAO
for the first time... and it has been high bandwidth, Class A and ZGF (zero global feedback) amplifiers
ever since.
Let me say a few things first how I auditioned during the last two days:
- the source for the entire session was a PONO player (SD card player with Ayre-designed output circuitry)
- all auditioning was done with my Sennheiser HD 800 since I didn't want to introduce too many variables.
My Senn's are slightly modded --> damping of the inner cavity with felt and a layer of very thin tissue as
acoustic "filter".
Despite the fact that some consider the Sennheiser HD 800's as overly bright or analytical this is not the case
when used with proper equipment --> every USB converter into a DAC still sounds a good deal less natural
than a PONO Player for instance. Even beats the R2R DAC that I also use. But that is another story...
OK, back to the Pioneer Super Linear Circuit:
Almost as expected the Pioneer circuit as employed by EUVL sounds very natural indeed and utterly transparent.
There is not a hint of background noise on the Sennheiser's, but with my daughters "cheap" Beats Solo a tiny
trace of hiss could be heard. But I was said that it will disappear when cased up, while being at the very
threshold of my hearing anyway.
Other than that I really had a hard time keeping the Pioneer SLC apart from the DAO... which is quite
exceptional considering the complexity and financial outlay for the DAO. On some pieces the Pioneer sounds very
much the same, on others you have to concentrate hard to hear a difference at all.
To me the DAO is the holy grail of SE headphone amplifiers --> DAO - Original-Ton
since it portrays music in a way that leaves nothing to be desired... everything sounds perfectly integrated
and as part of the picture, nothing stands out.
But the Pioneer comes very close, and it almost comes down to a matter of subjective and personal taste
rather than one really being better than the other. The Pioneer is a tiny bit brighter in general, for instance
on high pitched piano notes that stand out a bit more than on the DAO. There is no trace of harshness or grain
to be worried about. The Pioneer has a tight and well controlled bass with the DAO hitting a bit harder.
Both are capable of a kind of 'intimacy' when listening to your favourite tracks, with all the resolution even of
minute details you'd ever want (keyword atmosphere) Imaging with the Crossfeed circuit is slightly different
between the two but I couldn't point my finger to which one is better. ;-)
I also heard the F5 HA in comparison, but eventually left it out of the comparison simply because it was getting
too troublesome to switch source and headphones after every track between three amplifiers! The F5 HA as the
UTAiM are clearly from the same stable, but comparing ALL of them has to be left for another occasion.
and in comparison to the F5 HA and the DAO that I built during the last two years and that serve as my
benchmark headphone amplifiers since.
I have a bit of a journey behind me during the last 13 years with a good dozen headphone
amplifiers built, with various topologies from tubes over hybrid to solid state. The few that have
found my homepage might know that I was quite sceptical years ago about solid state amplifiers,
finding them sounding too cold and sterile for my taste...
Well this has changed after I got in contact with EUVL and after I heard his prototype DAO
for the first time... and it has been high bandwidth, Class A and ZGF (zero global feedback) amplifiers
ever since.
Let me say a few things first how I auditioned during the last two days:
- the source for the entire session was a PONO player (SD card player with Ayre-designed output circuitry)
- all auditioning was done with my Sennheiser HD 800 since I didn't want to introduce too many variables.
My Senn's are slightly modded --> damping of the inner cavity with felt and a layer of very thin tissue as
acoustic "filter".
Despite the fact that some consider the Sennheiser HD 800's as overly bright or analytical this is not the case
when used with proper equipment --> every USB converter into a DAC still sounds a good deal less natural
than a PONO Player for instance. Even beats the R2R DAC that I also use. But that is another story...
OK, back to the Pioneer Super Linear Circuit:
Almost as expected the Pioneer circuit as employed by EUVL sounds very natural indeed and utterly transparent.
There is not a hint of background noise on the Sennheiser's, but with my daughters "cheap" Beats Solo a tiny
trace of hiss could be heard. But I was said that it will disappear when cased up, while being at the very
threshold of my hearing anyway.
Other than that I really had a hard time keeping the Pioneer SLC apart from the DAO... which is quite
exceptional considering the complexity and financial outlay for the DAO. On some pieces the Pioneer sounds very
much the same, on others you have to concentrate hard to hear a difference at all.
To me the DAO is the holy grail of SE headphone amplifiers --> DAO - Original-Ton
since it portrays music in a way that leaves nothing to be desired... everything sounds perfectly integrated
and as part of the picture, nothing stands out.
But the Pioneer comes very close, and it almost comes down to a matter of subjective and personal taste
rather than one really being better than the other. The Pioneer is a tiny bit brighter in general, for instance
on high pitched piano notes that stand out a bit more than on the DAO. There is no trace of harshness or grain
to be worried about. The Pioneer has a tight and well controlled bass with the DAO hitting a bit harder.
Both are capable of a kind of 'intimacy' when listening to your favourite tracks, with all the resolution even of
minute details you'd ever want (keyword atmosphere
) Imaging with the Crossfeed circuit is slightly different between the two but I couldn't point my finger to which one is better. ;-)
I also heard the F5 HA in comparison, but eventually left it out of the comparison simply because it was getting
too troublesome to switch source and headphones after every track between three amplifiers! The F5 HA as the
UTAiM are clearly from the same stable, but comparing ALL of them has to be left for another occasion.
Attachments
Last edited:
Track list (partial):
- Rachmaninov: Piano Concerto no 2 (Dejan Lasic)
- Michael Wollny Trio: When The Sleeper Wakes
- Bugge Wesseltoft: Min By
- E.S.T. : Behind the Yashmak (Live)
- Dee Dee Bridgewater: Cheyenne (Live)
- Tchaikovsky: Violin Concertos [Maxim Vengerov]
- Sidsel Endresen: Out here, In there
- Lyle Mays: Lincoln Reviews His Notes
- Meshell Ndegeocello: The Chosen
- Helge Lien Trio: Diverted Dance
- Rachmaninov: Piano Concerto no 2 (Dejan Lasic)
- Michael Wollny Trio: When The Sleeper Wakes
- Bugge Wesseltoft: Min By
- E.S.T. : Behind the Yashmak (Live)
- Dee Dee Bridgewater: Cheyenne (Live)
- Tchaikovsky: Violin Concertos [Maxim Vengerov]
- Sidsel Endresen: Out here, In there
- Lyle Mays: Lincoln Reviews His Notes
- Meshell Ndegeocello: The Chosen
- Helge Lien Trio: Diverted Dance
I would have said myself 90% of the DAO for less than half the cost and complexity.
That says something since I am known to be a FET guy.
As I don't have a habbit of telling people how my amps sound, thus am very grateful that you took the time for the audition and comparison.
And we share more or less the same impressions.
For the GB I shall include a CCS bias daughter board to make the whole setup less sensitive to the power supply.
Patrick