I am looking for information about the Zenquito amp. It's a french design using lateral mosfets by J.M. Plantefève.
http://perso.wanadoo.fr/jm.plantefeve/sche.html
From what I've found on the internet I understand that Plantefève is called the french Nelson Pass. His amps are known for their transparency, musicality and simplicity. Fortunately his amps are of the push/pull type and thus be biased in AB. This makes for a compact amp (as opposed to Pass).
I have never had much interest in Passlabs amps. Mainly because of their bad objective performance (they measure terribly). However, I must admit that I have never heard any of them play...
What I am looking for are experiences from people who know this amp. I am particularly interested to find out what the specs of this amp are (THD vs. power, THD vs. Freq., S/N, DF, .., ..).
I am also interested to find out if there are any other goodies to look for: class AB designs with both super sound and (at least) reasonable (better than aleph) specs.
ABo
http://perso.wanadoo.fr/jm.plantefeve/sche.html
From what I've found on the internet I understand that Plantefève is called the french Nelson Pass. His amps are known for their transparency, musicality and simplicity. Fortunately his amps are of the push/pull type and thus be biased in AB. This makes for a compact amp (as opposed to Pass).
I have never had much interest in Passlabs amps. Mainly because of their bad objective performance (they measure terribly). However, I must admit that I have never heard any of them play...
What I am looking for are experiences from people who know this amp. I am particularly interested to find out what the specs of this amp are (THD vs. power, THD vs. Freq., S/N, DF, .., ..).
I am also interested to find out if there are any other goodies to look for: class AB designs with both super sound and (at least) reasonable (better than aleph) specs.
ABo
you can get more information on the french forum
http://www.homecinema-fr.com/forum
here:
http://www.homecinema-fr.com/forum/viewtopic.php?t=29719263
and there:
http://www.homecinema-fr.com/forum/viewtopic.php?t=29694422
http://www.homecinema-fr.com/forum
here:
http://www.homecinema-fr.com/forum/viewtopic.php?t=29719263
and there:
http://www.homecinema-fr.com/forum/viewtopic.php?t=29694422
Abo,
You are wrong on two key points, push pull amps can be class A if you bias them high enough and spec. have nothing, for the most part, to do with what an amplifier sounds like. Your common garden Yamaha or Pioneer reciever will spec. better than most high end amps.
You have a lot to learn.
Regards,
Jam
You are wrong on two key points, push pull amps can be class A if you bias them high enough and spec. have nothing, for the most part, to do with what an amplifier sounds like. Your common garden Yamaha or Pioneer reciever will spec. better than most high end amps.
You have a lot to learn.
Regards,
Jam
Apolon,
Thanks for the link. Although I don't really speak French I understand most of it.
To Fuling: You should really learn to read. If you read my message you will see that I never said anything other than that I am personally not very interested in Pass. I didn't say that these are bad amps at all. Hell, I've never even heard one play!
Given that I am an EE myself and that amps are electronics, I do care for specs. Perhaps more than they deserve. What can I do? I'm only human.
To Jam: What I meant was that Zenquito, as opposed to Pass, can be biased AB. It may just be my bad English. Remember that for a lot of forum members English is not their mother tongue. you should really try to be more respectful to others. I know it is hard when someone says something bad about your favourite designer, but still.
Oh well, like me, you're only human too. I forgive you.
Thanks for the link. Although I don't really speak French I understand most of it.
To Fuling: You should really learn to read. If you read my message you will see that I never said anything other than that I am personally not very interested in Pass. I didn't say that these are bad amps at all. Hell, I've never even heard one play!
Given that I am an EE myself and that amps are electronics, I do care for specs. Perhaps more than they deserve. What can I do? I'm only human.
To Jam: What I meant was that Zenquito, as opposed to Pass, can be biased AB. It may just be my bad English. Remember that for a lot of forum members English is not their mother tongue. you should really try to be more respectful to others. I know it is hard when someone says something bad about your favourite designer, but still.
Oh well, like me, you're only human too. I forgive you.
I´d love to invite you to build a pass amp but as I still haven´t finished mine I won´t comment.
Being not a big fan of power dissipation I originally planned to build the Zenquito.
After a while I thought that if nobody actually built this thing..., that is a sign for me to rather choose an Aleph3.
BTW.: The search-function on this forum is not all that bad
One example : http://www.diyaudio.com/forums/showthread.php?threadid=26872&highlight=
Being not a big fan of power dissipation I originally planned to build the Zenquito.
After a while I thought that if nobody actually built this thing..., that is a sign for me to rather choose an Aleph3.
BTW.: The search-function on this forum is not all that bad
One example : http://www.diyaudio.com/forums/showthread.php?threadid=26872&highlight=
Abo,
Point taken. I have built several versions of the Zenquito and I am currently working on a new version. It is a very nice soundung amp.
To get to work at it's best keep signal traces short and a good power supply helps. Also as you increase the bias the amp sounds a lot better.
In Mr. Pass's defence he used to design amps with low distortion many years ago none of which sound as his newer products with have higher distortion. You might just wan't to build one, you will be surprised.
Regards,
Jam
Point taken. I have built several versions of the Zenquito and I am currently working on a new version. It is a very nice soundung amp.
To get to work at it's best keep signal traces short and a good power supply helps. Also as you increase the bias the amp sounds a lot better.
In Mr. Pass's defence he used to design amps with low distortion many years ago none of which sound as his newer products with have higher distortion. You might just wan't to build one, you will be surprised.
Regards,
Jam
You can use:
babel.altavista.com
to translate most web sites. In this case, you will see that the specs are:
"At Exit into push-pull "common drain": its first diagrams have 20dB negative feedback, the level of DHT+bruit is lower than 0,05%, the band-width exceeds 200kHz. The profit is of 29dB (x28). Very goods for the enclosures with passive filtering and agreement bass reflex camera. The ratio damping higher than 100 make pure generators of tension of them."
where:
"exit" = output
"DHT" = THD
"bruit" = noise
"profit" = gain
"tension" = voltage
In other words, the specs are quite good. But even more importantly, as Jam pointed out, so is the sound.
babel.altavista.com
to translate most web sites. In this case, you will see that the specs are:
"At Exit into push-pull "common drain": its first diagrams have 20dB negative feedback, the level of DHT+bruit is lower than 0,05%, the band-width exceeds 200kHz. The profit is of 29dB (x28). Very goods for the enclosures with passive filtering and agreement bass reflex camera. The ratio damping higher than 100 make pure generators of tension of them."
where:
"exit" = output
"DHT" = THD
"bruit" = noise
"profit" = gain
"tension" = voltage
In other words, the specs are quite good. But even more importantly, as Jam pointed out, so is the sound.
"Fortunately his amps are of the push/pull type and thus be biased in AB. This makes for a compact amp (as opposed to Pass)."
The Zen V5 is push-pull.
"I have never had much interest in Passlabs amps. Mainly because of their bad objective performance (they measure terribly). "
Define 'bad', the Zen V5 has less than 0.08% THD at typical listening levels.
If you're not going to listen to your amp and are just going to watch it hooked up to a meter, just wire up a NE5532 to the input of the Zen V5 and the extra 100dB of feedback will make it look quite nice.
The Zen V5 is push-pull.
"I have never had much interest in Passlabs amps. Mainly because of their bad objective performance (they measure terribly). "
Define 'bad', the Zen V5 has less than 0.08% THD at typical listening levels.
If you're not going to listen to your amp and are just going to watch it hooked up to a meter, just wire up a NE5532 to the input of the Zen V5 and the extra 100dB of feedback will make it look quite nice.
It's a shame that most of the replies I get are not very constructive at all. Instead of actually helping someone, you are too busy defending your territories.
DJK: Thank you for pointing me at the ZEN V5. I didn't know that Passlabs had such a design. Most of the discussions on DIYAUDIO are about single-ended designs. I will most certainly look at it. As to the definition of bad: My current diy amp measures in at 0,002 % THD+N (1 kHz, 1W, 8 ohm). I think that a typical aleph would do >0,1 %? In comparison, that is bad, isn't it? Even 0,08% for ZEN5 doesn't look too good in comparison.
JoensD: I couldn't have posted unless had I searched the forum. Otherwise it would be complete fraud on my side (remember the checkbox when starting a new thread?). I couldn't find any information on objective performance of the Zenquito on this forum. This is my main interest.
If my post is read the way I intended it, you would notice that really I am a converted rationalist! I expected to be welcomed with open arms. It seems that tolerance towards other opinions isn't one of our values. Neither is reading.
DJK: Thank you for pointing me at the ZEN V5. I didn't know that Passlabs had such a design. Most of the discussions on DIYAUDIO are about single-ended designs. I will most certainly look at it. As to the definition of bad: My current diy amp measures in at 0,002 % THD+N (1 kHz, 1W, 8 ohm). I think that a typical aleph would do >0,1 %? In comparison, that is bad, isn't it? Even 0,08% for ZEN5 doesn't look too good in comparison.
JoensD: I couldn't have posted unless had I searched the forum. Otherwise it would be complete fraud on my side (remember the checkbox when starting a new thread?). I couldn't find any information on objective performance of the Zenquito on this forum. This is my main interest.
If my post is read the way I intended it, you would notice that really I am a converted rationalist! I expected to be welcomed with open arms. It seems that tolerance towards other opinions isn't one of our values. Neither is reading.
Abo,
my was just a friendly hint to use the search function.
Actually this is the most helpful, informative and friendly forum I´ve stumbled over so far!
You´ve got certain "parties" here in the forum.
One being the "pass-crew" and the "tube dudes" not necessarily hunting for low THD in the first place.
Then you have a lot people in the solid state and chip amp department who rather go for low THD primarily.
Most of them actually try all of these worlds. (which I for example also wanna explore to make my own opinion about class-a etc...)
I think you should drop Idefixes (my link above) an email or private message to talk with him about the zenquito.
Of course this will be quite difficult as he most probably have different speakers than you and no access to THD-measuring equipment.
But anyway it could be very informative.
Cheers & welcome
Jens
PS.: I still must have a PCB-layout made in Eagle somewhere so I could dig it out if you wanna try the amp.
my
was just a friendly hint to use the search function.Actually this is the most helpful, informative and friendly forum I´ve stumbled over so far!
You´ve got certain "parties" here in the forum.
One being the "pass-crew" and the "tube dudes" not necessarily hunting for low THD in the first place.
Then you have a lot people in the solid state and chip amp department who rather go for low THD primarily.
Most of them actually try all of these worlds. (which I for example also wanna explore to make my own opinion about class-a etc...)
I think you should drop Idefixes (my link above) an email or private message to talk with him about the zenquito.
Of course this will be quite difficult as he most probably have different speakers than you and no access to THD-measuring equipment.
But anyway it could be very informative.
Cheers & welcome
Jens
PS.: I still must have a PCB-layout made in Eagle somewhere so I could dig it out if you wanna try the amp.
"As to the definition of bad: My current diy amp measures in at 0,002 % THD+N (1 kHz, 1W, 8 ohm). I think that a typical aleph would do >0,1 %? In comparison, that is bad, isn't it? Even 0,08% for ZEN5 doesn't look too good in comparison."
To put things in perspective, consider speakers. Frequency Intermodulation Distortion, FMD, is much more anoying than THD.
A good 12" three way with a low crossover point to the midrange will still have 3% FMD at only 90dB. At this point it sounds congested and anoying.
OTOH, most people cannot tell that their amplifier is driven 6dB into clipping. Even with solid state. How much distortion is that? You tell me.
People obsessed with meter readings have lost their sense of perspective (if they ever had one).
To put things in perspective, consider speakers. Frequency Intermodulation Distortion, FMD, is much more anoying than THD.
A good 12" three way with a low crossover point to the midrange will still have 3% FMD at only 90dB. At this point it sounds congested and anoying.
OTOH, most people cannot tell that their amplifier is driven 6dB into clipping. Even with solid state. How much distortion is that? You tell me.
People obsessed with meter readings have lost their sense of perspective (if they ever had one).
ABO said:
True.
Also notice that Mr. Plantefeve amps have current feedback instead voltage feedback. Both Zenquito and Buzquito (or Mosquito) can be biased to class A or AB. You increase the quiescent current of output pair by increasing the collector resistors (68 ohm) of driver transistors ( 2N5416/3440). Or use two resistors in parallel in that place and a selector switch to disconnect one resistor of parallel resistor pair in order to switch amp between class A and AB.
Push pull amps tend to cancel even order harmonic distortion but can not cancel odd order so they became dominant. Hence the sound differences between single end and push pull Class A amps. To maintain the even order harmonic distortion Mr. Plantefève has came up with experimental design by totally eliminating the feedback network from output pair. This way second order distortions become dominant at the expense of worse overall THD figure.
Cheers,
An externally hosted image should be here but it was not working when we last tested it.
I am not sure you can use 2sk1530 and 2sj201 instead of 2sk1058 and 2sj162. Even if they are lateral type of mosfets as 2sk1058 and 2sj162, their negative temperature coefficient differs from 2sk1058 and 2sj162 i.e. you need to run much more current through them. Look also at postLuke said:
http://www.diyaudio.com/forums/showthread.php?postid=68174#post68174 and do more search on 2sk1530 and 2sj201 to be sure.
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