I do prefer the warm JLH, but AKSA was considered the best by my audio Club judgement
This way, i have to accept, that 16 experienced years considered the AKSA the best, i could see that i can hear more instruments than i can hear in the JLH.
This way i have some very intimate personal taste that turns me close to JLH
But, when i open my big mouth to say with one is better, i cannot say JLH anymore, as i always respected my friends judgment, this time was the first time i did not agree with them entirelly.
Also Graham Maynard, class A amplifier beat the JLH in the comparison made.
To say with one is best, i have to use some democratic and consensus information, not only my personal taste, this way, officially, AKSA is the first, Graham the second, and JLH the third.
But sometimes, in secret, hehe, i will have the pleasure hearing the third best wide world amplifier that i could heard those last 44 years.
Giselle bundchen is considered one of the most beautifull woman in earth, i have to say that, because all mankind this way understand that beauty, but to go to my bed, at nigth, i will go with my damn, noisy, nervous, without good education, not kind, but lovely war and wonderfull "Spanish beauty!, she is my wife.
To a happy party i will go with Bundchen, and the sound will be AKSA.
To hear one DVD, with wonderfull bass, i will go with some silent woman, and the sound will be the one made by Graham Maynard.
regards,
Carlos
This way, i have to accept, that 16 experienced years considered the AKSA the best, i could see that i can hear more instruments than i can hear in the JLH.
This way i have some very intimate personal taste that turns me close to JLH
But, when i open my big mouth to say with one is better, i cannot say JLH anymore, as i always respected my friends judgment, this time was the first time i did not agree with them entirelly.
Also Graham Maynard, class A amplifier beat the JLH in the comparison made.
To say with one is best, i have to use some democratic and consensus information, not only my personal taste, this way, officially, AKSA is the first, Graham the second, and JLH the third.
But sometimes, in secret, hehe, i will have the pleasure hearing the third best wide world amplifier that i could heard those last 44 years.
Giselle bundchen is considered one of the most beautifull woman in earth, i have to say that, because all mankind this way understand that beauty, but to go to my bed, at nigth, i will go with my damn, noisy, nervous, without good education, not kind, but lovely war and wonderfull "Spanish beauty!, she is my wife.
To a happy party i will go with Bundchen, and the sound will be AKSA.
To hear one DVD, with wonderfull bass, i will go with some silent woman, and the sound will be the one made by Graham Maynard.
regards,
Carlos
What is the difference between the AKSA 100 and the JLH 80w mosfet
I would be most grateful if anyone who has heard these 2 amps could offer their thoughts on the differences in sound reproduction between the 2.
I currently have a JLH 80w with upgraded feedback and decoupling capacitors on the amplifier board, and a higher specification power supply using 10 000 muF Elna Cerafines, a larger transformer and UG8DT diodes.
I am wondering whether to make another powers supply to make it dual mono, or throw the towel in and get an AKSA.
Regards,
John
I would be most grateful if anyone who has heard these 2 amps could offer their thoughts on the differences in sound reproduction between the 2.
I currently have a JLH 80w with upgraded feedback and decoupling capacitors on the amplifier board, and a higher specification power supply using 10 000 muF Elna Cerafines, a larger transformer and UG8DT diodes.
I am wondering whether to make another powers supply to make it dual mono, or throw the towel in and get an AKSA.
Regards,
John
Foxy - look back through this thread. I used to have had mono bloc JLH80Ws - the high current PSU is not very well designed (the -ive reference is modulated by the load on the +ve rail and vice versa) - don't bother to build another.
Here are my latest thoughts:
Power Amps:
1) AKSA 100N
2) AKSA 55N/P61 (Modified)
3) P3A with Sanken o/p trannies, dual mono etc (converted to emitter follower o/p)
4) JLH 80W Mosfet amps with improved low current regs and unregulated high current supplies, dual mono.
5) About 20 variations (including my own variations) of the Borbely 60W mosfet/DC100 amps (not built on official boards).
6) Mini Crescendo
7) Maplin Mosfet amps
8) Aleph 5 (Aleph 30 input stage)
15) TDA1514
Aleph 5 slipping badly down the rankings after extended listening
Here are my latest thoughts:
Power Amps:
1) AKSA 100N
2) AKSA 55N/P61 (Modified)
3) P3A with Sanken o/p trannies, dual mono etc (converted to emitter follower o/p)
4) JLH 80W Mosfet amps with improved low current regs and unregulated high current supplies, dual mono.
5) About 20 variations (including my own variations) of the Borbely 60W mosfet/DC100 amps (not built on official boards).
6) Mini Crescendo
7) Maplin Mosfet amps
8) Aleph 5 (Aleph 30 input stage)
15) TDA1514
Aleph 5 slipping badly down the rankings after extended listening
Many thanks Dave - is it worthy me coverting the 55V regulators?
Thanks very much for your help Dave.
In the short term absence of funds, to power my Ellis Audio 1801 floor standers, is it worth me running the JLH 80W with unregulated high voltage rails, as I already use a 45-0-45 transformer?
Also, if and when I buy and AKSA, do you recommend I go for the 100 or 55?
Would you recommend I reuse my 4.7 muF MCAP feedback caps (they are fab), and the Panasonc HFZ decoupling electrolytics instead of the Nirvana plus upgrade?
Thanks again. It is very difficult finding anyone who has worked with these amps, perhaps because of the defects you have mentioned.
Regards,
john
Thanks very much for your help Dave.
In the short term absence of funds, to power my Ellis Audio 1801 floor standers, is it worth me running the JLH 80W with unregulated high voltage rails, as I already use a 45-0-45 transformer?
Also, if and when I buy and AKSA, do you recommend I go for the 100 or 55?
Would you recommend I reuse my 4.7 muF MCAP feedback caps (they are fab), and the Panasonc HFZ decoupling electrolytics instead of the Nirvana plus upgrade?
Thanks again. It is very difficult finding anyone who has worked with these amps, perhaps because of the defects you have mentioned.
Regards,
john
Hi John,
I think the 1801s are a reasonable load, however I would not recommend using +/-70V rails with only 2 pairs of fets for low impedance loads - it also depends on the size of your heatsinks and the voltage rating of the actual fets. +/- 58V is more "normal" for two pairs of Hitachi fets.
It is very difficult to avoid ground loops in a stereo amp with only one PSU. I seem to remember JLH himself making the point that ideally the 2 channels should occupy the same physical space.
If you want to stick with the JLH80, it may be best to buy 2 new transformers 40-0-40 or 35-0-35 and use separate unreg PSUs per channel.
The amp is very sensitive to the quality of the low current regs for the front end and VAS. I found that JLHs reg circuit with a current mirror and FET pass tr gave good results. The o/p impedance needs to be much lower than in JLH's original design, whilst retaining fast transient response.
With 1801s (about 85dB/W?) I recommend the 100W.
I've never used Mcaps but they are too low in value for the AKSA and too big physically.
I use HFZs in my 55W on the rails. I think (but have not done enough trials to be sure) that I prefer Silmics and Stargets to all the Pana caps.
IMVHO it is really difficult (if not impossible) to get a FET amp to sound as good as well designed biploar amp (Crash helmet and ear plugs are now fitted!!!).
Dave
I think the 1801s are a reasonable load, however I would not recommend using +/-70V rails with only 2 pairs of fets for low impedance loads - it also depends on the size of your heatsinks and the voltage rating of the actual fets. +/- 58V is more "normal" for two pairs of Hitachi fets.
It is very difficult to avoid ground loops in a stereo amp with only one PSU. I seem to remember JLH himself making the point that ideally the 2 channels should occupy the same physical space.
If you want to stick with the JLH80, it may be best to buy 2 new transformers 40-0-40 or 35-0-35 and use separate unreg PSUs per channel.
The amp is very sensitive to the quality of the low current regs for the front end and VAS. I found that JLHs reg circuit with a current mirror and FET pass tr gave good results. The o/p impedance needs to be much lower than in JLH's original design, whilst retaining fast transient response.
With 1801s (about 85dB/W?) I recommend the 100W.
I've never used Mcaps but they are too low in value for the AKSA and too big physically.
I use HFZs in my 55W on the rails. I think (but have not done enough trials to be sure) that I prefer Silmics and Stargets to all the Pana caps.
IMVHO it is really difficult (if not impossible) to get a FET amp to sound as good as well designed biploar amp (Crash helmet and ear plugs are now fitted!!!).
Dave
Hey Dudes,
i have been hearing a lot of praise for this JLH amp, but I have no idea what it looks like. Where is the latest schematic? IS it class A because I am looking for a good amp to drive my Magnepan MMGs. I presently have a zenquitto amp running them but they are dreadfully awful.
Thanks Yall
Lawrence
i have been hearing a lot of praise for this JLH amp, but I have no idea what it looks like. Where is the latest schematic? IS it class A because I am looking for a good amp to drive my Magnepan MMGs. I presently have a zenquitto amp running them but they are dreadfully awful.
Thanks Yall
Lawrence
Hey all here is my contribution:
SOLID STATE AMPS:
Hiraga Le Monstre with regulated supply
- hard to beat about the minimum power I can get away with with normal speakers
JLH 1996 regulated monoblocks
- very good sounds natural due to lo to moderate negative feedback and low damping factor
Ampslab HX100
- Hard to beat in the 100-150W range so easy to build / setup very stable and quiet
Various LM3886 amps.
- monoblocks/dual stereo etc etc
Will get you pretty decent sound easily but nothing special in my humble opinion.
TUBE AMPS:
Uniamp KT88 PP triode mode monoblocks
- very good extremely clear/dynamic treble easy to drive
huge sound for 17-30 watts triode/pentode
6AS7G triode PP class A
- underpowered but what it does have is good.
SOLID STATE AMPS >500W
Full range but also suitable for PA use in no particular order:
Quasi's ACTRK600 stereo high power version
- very reliable in party situation rans relatively cool driving three large horn loaded cabs at four ohms each channel outside for approx 5 hours at party levels last weekend
Ampslab HX350 monoblocks with double output stage
- very reliable in party situation stable into low impedance loads
will drive 2 ohm subwoofers at 500W+ no problems
2 monos can be bridged for 2000W @ 4 ohm
Anthony Holtons AV800
Nice clean sound when used for subwoofers in party situation
delivers the rated 800 easily survives into 2 ohm loads without much drama
Next project = 20W Le Classe A Hiraga.
-Dan
SOLID STATE AMPS:
Hiraga Le Monstre with regulated supply
- hard to beat about the minimum power I can get away with with normal speakers
JLH 1996 regulated monoblocks
- very good sounds natural due to lo to moderate negative feedback and low damping factor
Ampslab HX100
- Hard to beat in the 100-150W range so easy to build / setup very stable and quiet
Various LM3886 amps.
- monoblocks/dual stereo etc etc
Will get you pretty decent sound easily but nothing special in my humble opinion.
TUBE AMPS:
Uniamp KT88 PP triode mode monoblocks
- very good extremely clear/dynamic treble easy to drive
huge sound for 17-30 watts triode/pentode
6AS7G triode PP class A
- underpowered but what it does have is good.
SOLID STATE AMPS >500W
Full range but also suitable for PA use in no particular order:
Quasi's ACTRK600 stereo high power version
- very reliable in party situation rans relatively cool driving three large horn loaded cabs at four ohms each channel outside for approx 5 hours at party levels last weekend
Ampslab HX350 monoblocks with double output stage
- very reliable in party situation stable into low impedance loads
will drive 2 ohm subwoofers at 500W+ no problems
2 monos can be bridged for 2000W @ 4 ohm
Anthony Holtons AV800
Nice clean sound when used for subwoofers in party situation
delivers the rated 800 easily survives into 2 ohm loads without much drama
Next project = 20W Le Classe A Hiraga.
-Dan
diy amp comparison
has anyone ever had a chance to do a direct comparison in sound quality of diy amps? The models I'm most interested in are MikeB's SymAsym5, Elliot P3A and the AKSA (latest version).
Any info on the sound quality of diy amps would be greatly appreciated. I've read a ton of threads here and it seems like most of the diy amps are very good, but I want to build the best, or at least one of the best, 100+Watt amps.
has anyone ever had a chance to do a direct comparison in sound quality of diy amps? The models I'm most interested in are MikeB's SymAsym5, Elliot P3A and the AKSA (latest version).
Any info on the sound quality of diy amps would be greatly appreciated. I've read a ton of threads here and it seems like most of the diy amps are very good, but I want to build the best, or at least one of the best, 100+Watt amps.
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