Re: Re: Zenquito
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
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fab: Unfortunately I have neither built or heard this amp but looking at the internet site, in my opinion, the "Buzzquito" design appears even more interesting because of the cascode input stage. The site (the french is my first language) indicates that the "cascode" immunes to power supply noise (even the 10V zener could be reduced further down). So, for a couple of transistors more the Buzzquito looks to me like an improved Zenquito design.
As for other goodies class AB designs with good sound and specs you can have a look at the "classic" DH-200/220/XL280 amps.
I am also an EE and I am looking for both good sound and good specs either. I believe that the published classic specs really do not say it all in the behavior of an amplifier but an amplifier with relatively "bad" classic spec is not very appealing at first sight.
When you built your amp, let us know how it sounds and measures!
I am looking for information about the Zenquito amp. It's a french design using lateral mosfets by J.M. Plantefève.fab said:
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
________________________________
fab: Unfortunately I have neither built or heard this amp but looking at the internet site, in my opinion, the "Buzzquito" design appears even more interesting because of the cascode input stage. The site (the french is my first language) indicates that the "cascode" immunes to power supply noise (even the 10V zener could be reduced further down). So, for a couple of transistors more the Buzzquito looks to me like an improved Zenquito design.
As for other goodies class AB designs with good sound and specs you can have a look at the "classic" DH-200/220/XL280 amps.
I am also an EE and I am looking for both good sound and good specs either. I believe that the published classic specs really do not say it all in the behavior of an amplifier but an amplifier with relatively "bad" classic spec is not very appealing at first sight.
When you built your amp, let us know how it sounds and measures!
Re: Re: Re: Zenquito
Instead of using current sourses you can also try cascoding input fets with 2SJ109 and 2sk389 encapsulated matched pairs like one of the Zenquito builders has done.
Set of mesurements of one Zenquite built you can find at http://perso.planetis.com/pcharlet/mesuresa0.html
This paricular plot shows THD of his amp with 10 Volts input voltage producing 1.6 w into 8 Ohms load.
Instead of using current sourses you can also try cascoding input fets with 2SJ109 and 2sk389 encapsulated matched pairs like one of the Zenquito builders has done.
An externally hosted image should be here but it was not working when we last tested it.
Set of mesurements of one Zenquite built you can find at http://perso.planetis.com/pcharlet/mesuresa0.html
This paricular plot shows THD of his amp with 10 Volts input voltage producing 1.6 w into 8 Ohms load.
An externally hosted image should be here but it was not working when we last tested it.
Thanks guys
Argo, Thank you for the last link. That is exactly what I've been looking for. The measurements look scary indeed...
OTOH, I feel that the only way to find out about the sound is to take the plunge and actually build one. So I've decided to build Zenquito. According to Plantfeve, Zenquito Evolution is his best amp at +/- 42 Volt (for which I already have complete PSU).
I've ordered the PCB's directly from him. I ordered matched pairs of laterals from tech-diy.com and riken ohms from acoustics-dimension.com. When the amp is finished I will definately report back to you. Don't expect any flashy looking cabinets though, just a straightforward built amp, made to sound as good as it can.
regards,
ABo
Argo, Thank you for the last link. That is exactly what I've been looking for. The measurements look scary indeed...
OTOH, I feel that the only way to find out about the sound is to take the plunge and actually build one. So I've decided to build Zenquito. According to Plantfeve, Zenquito Evolution is his best amp at +/- 42 Volt (for which I already have complete PSU).
I've ordered the PCB's directly from him. I ordered matched pairs of laterals from tech-diy.com and riken ohms from acoustics-dimension.com. When the amp is finished I will definately report back to you. Don't expect any flashy looking cabinets though, just a straightforward built amp, made to sound as good as it can.
regards,
ABo
Re: Thanks guys
Borbelyaudio is one place you can get matched pairs of BL or V grade jfets at reasonable price. He also carries other exotic components like tantalum resistors and various brands of "audiophile" capacitors, etc.
To have the input fets matched has even greater importance.ABO said:
Borbelyaudio is one place you can get matched pairs of BL or V grade jfets at reasonable price. He also carries other exotic components like tantalum resistors and various brands of "audiophile" capacitors, etc.
Re: Thanks guys
Plantfeve has also published this one:
http://perso.wanadoo.fr/jm.plantefeve/nrds1.jpg
This one gives a lot better result for THD at high power levels. It may be explained by the use of differential input pair. In fact, it is similar to Erno Borbely (http://www.borbelyaudio.com/) designs (designer of DH-200 amp) but with lower feedback and cascode VAS stage. Jean Hiraga (known audiophile) gives very good comments about this Plantfeve amp in terms of sounding quality.
ABO said:
Plantfeve has also published this one:
http://perso.wanadoo.fr/jm.plantefeve/nrds1.jpg
This one gives a lot better result for THD at high power levels. It may be explained by the use of differential input pair. In fact, it is similar to Erno Borbely (http://www.borbelyaudio.com/) designs (designer of DH-200 amp) but with lower feedback and cascode VAS stage. Jean Hiraga (known audiophile) gives very good comments about this Plantfeve amp in terms of sounding quality.
Why simple?
I don't see the advantage of so-called simple designs. Do you think they are easier to build? I don't think they are.
Looking at the entire project, cabinet, power supply, amplifier board and wiring, a simple amp is usually only more simple with respect to the actual amplifier schematic. The difference in cost and time invested is neglectable.
Also I don't think that amps with complex schematics are more difficult to build. So long as you put every component in the right place and follow the instructions regarding adjustments etc., there really is no difference with simple amps.
So what is it, then? Is it that you think that simple amps sound better?
Please let me know opinion.
ABo
argo said:
not so simple any more
I don't see the advantage of so-called simple designs. Do you think they are easier to build? I don't think they are.
Looking at the entire project, cabinet, power supply, amplifier board and wiring, a simple amp is usually only more simple with respect to the actual amplifier schematic. The difference in cost and time invested is neglectable.
Also I don't think that amps with complex schematics are more difficult to build. So long as you put every component in the right place and follow the instructions regarding adjustments etc., there really is no difference with simple amps.
So what is it, then? Is it that you think that simple amps sound better?
Please let me know opinion.
ABo
Re: Why simple?
In my opinion, as you indicated, there is only a very small gain of time using a "simple" design (maybe easier to troubleshoot in case of problems?). Personaly, I do not care about the number of components used. The goal is to have the "best" amplifier driver circuit. The cost of the driver circuit is negligeable compared to the rest of the amp (power supply, power transistors, etc.).
Regarding the sound of simple designs, some peoples say that the more there have components, the more you can introduce problems (phase shifts, distorsion, etc.), thus justifying simple designs. I think it is not the proper perspective. When components are used in a design, it is for a known purpose. If the purpose is not justified then it is simply a bad complex design!
However, it is probably a good approach to use not more than 2 gain stages to avoid complex problems. Having said that, using a more "stable" stage that includes sometimes more components can be a good justification.
Remember that there is no definition of "good" sounding. Some peoples listening to one amp may have quite different opinions on it. For example, when a good amplifier reveals all the details in the music, it includes also the defects of the recordings or sources, etc... Another example, some peoples do not like to hear the real "mechanical sound" of the hammers on the ropes in a piano.
ABO said:
In my opinion, as you indicated, there is only a very small gain of time using a "simple" design (maybe easier to troubleshoot in case of problems?). Personaly, I do not care about the number of components used. The goal is to have the "best" amplifier driver circuit. The cost of the driver circuit is negligeable compared to the rest of the amp (power supply, power transistors, etc.).
Regarding the sound of simple designs, some peoples say that the more there have components, the more you can introduce problems (phase shifts, distorsion, etc.), thus justifying simple designs. I think it is not the proper perspective. When components are used in a design, it is for a known purpose. If the purpose is not justified then it is simply a bad complex design!
However, it is probably a good approach to use not more than 2 gain stages to avoid complex problems. Having said that, using a more "stable" stage that includes sometimes more components can be a good justification.
Remember that there is no definition of "good" sounding. Some peoples listening to one amp may have quite different opinions on it. For example, when a good amplifier reveals all the details in the music, it includes also the defects of the recordings or sources, etc... Another example, some peoples do not like to hear the real "mechanical sound" of the hammers on the ropes in a piano.
Re: Why simple?
Sorry for the delayed post.
My reply to your previous post was written with smilies so I kind of hoped it to be received with little grain of salt. Actually I pretty much agree with you regarding complex designs.
Following is only my personal opinion and doesn’t pretend to be the "correct way" to build amps
For me simple designs have been easier to build because of the way I have built most of my amps. What I usually do, I use the same, once already built cabinet and PS (tranny needs to be changed sometimes though) and only swap the circuit board and some wires. I agree that complex schematics are not harder to build if you use the dedicated PCB. I rarely do. Though I like to design PCB -s on computer I have newer got around to actually manufacture most of them because of the impatience or added cost involved ordering them. I use veroboard or P to P wiring or mixture or both. On the other hand doing good P-P wiring can actually be more time consuming and messy than soldering the components straight to the PCB. Sometimes doing these those P to P boards I swear to myself that this is gonna be a last time I will use this technique and will definitely order proper PCB next time. Somehow this has newer happened very often.
Regarding the sound qualities between simple and complex design I also must agree with fab, that when the components in more complex design are used for a justified purpose, the sound quality and stability of the amp can be improved but also that fewer gain stages avoid complex problems. Also my experience have been that these so-called simple designs tend to be harder to adjust for dc offset and quiescent current, than well thought out complex designs. So there is some thin line between a simple and complex design when one or another is justified and this is highly based on personal experience and expectations.
Cheers,
Argo
ABO said:
Sorry for the delayed post.
My reply to your previous post was written with smilies so I kind of hoped it to be received with little grain of salt. Actually I pretty much agree with you regarding complex designs.
Following is only my personal opinion and doesn’t pretend to be the "correct way" to build amps
For me simple designs have been easier to build because of the way I have built most of my amps. What I usually do, I use the same, once already built cabinet and PS (tranny needs to be changed sometimes though) and only swap the circuit board and some wires. I agree that complex schematics are not harder to build if you use the dedicated PCB. I rarely do. Though I like to design PCB -s on computer I have newer got around to actually manufacture most of them because of the impatience or added cost involved ordering them. I use veroboard or P to P wiring or mixture or both. On the other hand doing good P-P wiring can actually be more time consuming and messy than soldering the components straight to the PCB. Sometimes doing these those P to P boards I swear to myself that this is gonna be a last time I will use this technique and will definitely order proper PCB next time. Somehow this has newer happened very often.
Regarding the sound qualities between simple and complex design I also must agree with fab, that when the components in more complex design are used for a justified purpose, the sound quality and stability of the amp can be improved but also that fewer gain stages avoid complex problems. Also my experience have been that these so-called simple designs tend to be harder to adjust for dc offset and quiescent current, than well thought out complex designs. So there is some thin line between a simple and complex design when one or another is justified and this is highly based on personal experience and expectations.
Cheers,
Argo
Re: Re: Re: Re: Zenquito
Hello,
To announce all the same that one should not confuse Zenquito and Zenquito Evo. which are not identical to the level of the stage of entered. So they do not have the same sound completely. For Boris, it made both...
Zenquito Evo. which is an evolution of Mosquito, without Cascode in the stage of entered, Fet used are low capacity and support values of more important tension, of or the suppression of the cascode until tensions of approximately 40/50 Volts.
To have compared this Zenquito with Mosquito, I can say that the differences are very tiny, and I wonder what one could find well like difference with measurements, to which I do not attach any importances, only the result of the ear counts with my taste and I have a very clear preference for polarization in class A. (the alim must be with the height and without residual undulation).
The sound for Zenquito is softer than for the others the others and I would say with a tendency more tube... even report for Crescendo Millennium of the Elektor review. But like one says on our premises "the taste and the colors"...
@ + JF
argo said:
Hello,
To announce all the same that one should not confuse Zenquito and Zenquito Evo. which are not identical to the level of the stage of entered. So they do not have the same sound completely. For Boris, it made both...
Zenquito Evo. which is an evolution of Mosquito, without Cascode in the stage of entered, Fet used are low capacity and support values of more important tension, of or the suppression of the cascode until tensions of approximately 40/50 Volts.
To have compared this Zenquito with Mosquito, I can say that the differences are very tiny, and I wonder what one could find well like difference with measurements, to which I do not attach any importances, only the result of the ear counts with my taste and I have a very clear preference for polarization in class A. (the alim must be with the height and without residual undulation).
The sound for Zenquito is softer than for the others the others and I would say with a tendency more tube... even report for Crescendo Millennium of the Elektor review. But like one says on our premises "the taste and the colors"...
@ + JF
Bricolo said:
Aîe Aîe Aîe
You found my measurments on my Zenquito on my site.
I have to make them again, but I have first to find a good sound card (I look for a Audigy 2 ZS), a good measure network (attenuators without distorsion at the output of the amplifier) and a good sinus generator (the H3, it's him
). The main distorsion on all the diagrams I put on my site comes from the soundcard input. I made many measure now and this input is very quickly saturated.I'm sure that the Zenquito is quite better than this, but iI'm working on a better way to measure it.
Philippe (shame on me
)
I made new measurements on my Zenquito this week :
An Audigy2ZS as sound card :
You have the results here :
on 8 ohms (a power resistor) :
http://phil.charlet.free.fr/mesuresa4.html
On 4 ohms :
http://phil.charlet.free.fr/mesuresa5.html
And with a tube preamplifier (5725) :
http://phil.charlet.free.fr/mesuresa6.html
Philippe
An Audigy2ZS as sound card :
You have the results here :
on 8 ohms (a power resistor) :
http://phil.charlet.free.fr/mesuresa4.html
On 4 ohms :
http://phil.charlet.free.fr/mesuresa5.html
And with a tube preamplifier (5725) :
http://phil.charlet.free.fr/mesuresa6.html
Philippe
While trying out my schoolboy french on your link, I found this -
http://www.homecinema-fr.com/forum/viewtopic.php?t=29814985&sid=695001df
seem's Gregs amps are everywhere.
http://www.homecinema-fr.com/forum/viewtopic.php?t=29814985&sid=695001df
seem's Gregs amps are everywhere.
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