Yes it does, and very well!!!!
Thank you very much.
Tonight is THE NIGHT WHEN IT WILL HAPPEN.
I have the fets, both IRFP250 and 260/IR. I have a couple big heatsinks, a 25 volt powersupply and a lot of other things...
I just have to strip apart the transformer and wind 40 more turns.
Thank you very much for all great ideas and support.
Johannes.
Hi Circlomanen,
Great, look forward to hearing (well reading) as to how you get on 🙂
Best wishes,
Susan.
Circlomanen said:
Great, look forward to hearing (well reading) as to how you get on 🙂
Best wishes,
Susan.
The sound of different Mosfets?
Hi Susan,
Would you care to venture a guess on how effect different mosfets will have on the sound of your design?
I re-read the entire thread last night(for the 3rd time) and noticed how you tries MRF148's in place of the IRFP140/150's and said distortion dropped to half. but, I don't think you commented on the sound.
Although, you did imply that close matching of the FET's may be more important.
I ask this because I'm probably taking Bear up on his generous offer for closely matched Hitatchi 2SJ49's.
Do you think most FET's will be more similar in sound than dis-similar?
Hi Susan,
Would you care to venture a guess on how effect different mosfets will have on the sound of your design?
I re-read the entire thread last night(for the 3rd time) and noticed how you tries MRF148's in place of the IRFP140/150's and said distortion dropped to half. but, I don't think you commented on the sound.
Although, you did imply that close matching of the FET's may be more important.
I ask this because I'm probably taking Bear up on his generous offer for closely matched Hitatchi 2SJ49's.
Do you think most FET's will be more similar in sound than dis-similar?
IT IS ALIVE!!!!!
Its playing stockfish records behind me in my lab on my labspeaker.
IT SOUNDS WAY BETTER THEN I THOUGHT!!!
This is just an experiment and I use a mains transformer as input transformer connected backwards, a 50 VA toroid with 24 volts "primary" and 2*115 volt winding as secondary. Im using a 800 mA 20 volt regulated powersupply but i can easily get my neighbours to start knocking on the walls (!) with the amp. Its a bit "dark" sounding but I blame the input transformer . It sounds very "alive" and I instantly like and enjoy the sound!
Tomorrow I will have to start winding better input transformers.
THIS IS A GREAT AMP!!!!!!! (IMHO)
Thanx Susan...
Johannes.
Its playing stockfish records behind me in my lab on my labspeaker.
IT SOUNDS WAY BETTER THEN I THOUGHT!!!
This is just an experiment and I use a mains transformer as input transformer connected backwards, a 50 VA toroid with 24 volts "primary" and 2*115 volt winding as secondary. Im using a 800 mA 20 volt regulated powersupply but i can easily get my neighbours to start knocking on the walls (!) with the amp. Its a bit "dark" sounding but I blame the input transformer . It sounds very "alive" and I instantly like and enjoy the sound!
Tomorrow I will have to start winding better input transformers.
THIS IS A GREAT AMP!!!!!!! (IMHO)
Thanx Susan...
Johannes.
Re: IT IS ALIVE!!!!!
Hi Circlomanen,
that's fine !
I have a bad input transformer (2x115v, 2x16V 2A) and it sounds very bad with too mutch distr .
which circuit do you build and which changes do you make ?
What about the current through the mosfet's ?
How do you control - mosfet-bias it ?
per mVolt or per mAmpere.
I use through any IRF 530N Mosfet 125mA.
See http://bauteile-fuer-die-elektronik.de/projekte/Zeus/project/ .
best wiches.
-uwe
Hi Circlomanen,
that's fine !
I have a bad input transformer (2x115v, 2x16V 2A) and it sounds very bad with too mutch distr .
which circuit do you build and which changes do you make ?
What about the current through the mosfet's ?
How do you control - mosfet-bias it ?
per mVolt or per mAmpere.
I use through any IRF 530N Mosfet 125mA.
See http://bauteile-fuer-die-elektronik.de/projekte/Zeus/project/ .
Circlomanen said:
best wiches.
-uwe
The original circuit but i use IRFP250/IR. Bias is set with a 6 volt battery and a 47 k pot (I had it lying on my table). I measure the quisent current over two 0,15 ohm 5 watt resistors that I put between the drains an positive rails,one to each mosfet. The amp is a rats nest version with alligator leds and the whole lot, but it works very good!!!!! The bias is totaly stable at 0,007 volts across the resistors, it hasnt changed 1% in over 2 hours.
The output transformer is threefilar -winded so the turnratio is 2:1.
CAR-ZEUS
Im thinking about a car version of the Zeus-amp. 13-14 volt rail, IRFP3703/IR and a 1:3 stepup output transformer.
The IRFP3703/IR has (I think) 210S transconduktans.
It should be able to give some serious current!
Anybody having any thoughts or ideas??
Im thinking about a car version of the Zeus-amp. 13-14 volt rail, IRFP3703/IR and a 1:3 stepup output transformer.
The IRFP3703/IR has (I think) 210S transconduktans.
It should be able to give some serious current!
Anybody having any thoughts or ideas??
Susan, have you noticed your new title? Everyboby else can have a title, you only have to donate a small amount of money, button below and above for this.
Susan have you tested RightMark Audio Analyzer? Russion freeware, excellent as long as you have a PC and a soundcard. With this software you can get a fast picture of the performance. If you already have a PC with audio in and out this is for free!
http://audio.rightmark.org
Here is some fast measurements I did on my TPA6120 based amp (which I know you also has dealt with!)
Susan have you tested RightMark Audio Analyzer? Russion freeware, excellent as long as you have a PC and a soundcard. With this software you can get a fast picture of the performance. If you already have a PC with audio in and out this is for free!
http://audio.rightmark.org
Here is some fast measurements I did on my TPA6120 based amp (which I know you also has dealt with!)
Re: IT IS ALIVE!!!!!
Hi Johannes,
Excellent, I a very pleased you have got such good results.
The quality of the input transformer is important and any mis-match here will affect everything all the way along.
I have found surprisingly good results with the two toroids I have tried (30VA and 15VA), but not all will works so well and ordinary small EI dual chamber bobbin mains transformers will be poor at best.
Remember when testing that the mosfet capacitance that the input transformer is driving is the gate to drain, not the gate to source.
The loudspeaker will have much more of an effect on the sound as there is no feedback and it is worth trying different ones should you have any to hand.
For the input transformers you may have problems if you try to bifilar wind the secondaries as the interwinding capacitance is high. I tried this for an interstage transformer (2 stage amp) when I was doing my original design work ten years ago and the results were not good.
What source are you driving the input transformer with?
And perhaps what you are hearing, in part at least, is just the quality of the source material?
I did find that winding transformers became quite an engrossing part of the design work, particularly as they are the main components in the amplifier.
When you have two amps running you will be able to hear the sound staging as well.
Great 🙂
Best wishes,
Susan.
Hi Johannes,
Circlomanen said:
Excellent, I a very pleased you have got such good results.
The quality of the input transformer is important and any mis-match here will affect everything all the way along.
I have found surprisingly good results with the two toroids I have tried (30VA and 15VA), but not all will works so well and ordinary small EI dual chamber bobbin mains transformers will be poor at best.
Remember when testing that the mosfet capacitance that the input transformer is driving is the gate to drain, not the gate to source.
The loudspeaker will have much more of an effect on the sound as there is no feedback and it is worth trying different ones should you have any to hand.
For the input transformers you may have problems if you try to bifilar wind the secondaries as the interwinding capacitance is high. I tried this for an interstage transformer (2 stage amp) when I was doing my original design work ten years ago and the results were not good.
What source are you driving the input transformer with?
And perhaps what you are hearing, in part at least, is just the quality of the source material?
I did find that winding transformers became quite an engrossing part of the design work, particularly as they are the main components in the amplifier.
When you have two amps running you will be able to hear the sound staging as well.
Great 🙂
Best wishes,
Susan.
Re: The sound of different Mosfets?
Hi darkmoebius,
A good question 🙂
I think that the overall sound will be "of a type" the same way that there tends to be a "valve sound" and a "solid state sound".
I think that my amplifier falls somewhere between the two, but this is very subjective and depends much upon one's personal hearing.
I know for mine that this is not the same as many other people's since I have more sensitivity to phase but possibly less to distortion (there is usually a trade off in these things) in the same way that my night vision is very good (2Gen+) but my colour is not so good as far as light levels go and I need brighter illumination to read etc.
I would think that technology types will be very similar however I do note that the IRFP150 has lower distortion by 0.1% or more than a IRFP140 and this is certainly audible to the trained/sensitive ear.
I used the MRF148's to illustrate that it was well worth while in experimenting with different mosfet types and bias levels. I would have to build a proper stereo amp for the living room to drive my main speakers to be able to give any reasonable comments as I don't think my little mono setup is really adequate for this.
And my 8 ohm load is (fortunately perhaps) very boring to listen to 🙂
Close matching of the fets should help a lot, and the 2SJ49s when biased correctly for the type should be good.
Hope this helps.
Best wishes,
Susan.
Hi darkmoebius,
A good question 🙂
darkmoebius said:
I think that the overall sound will be "of a type" the same way that there tends to be a "valve sound" and a "solid state sound".
I think that my amplifier falls somewhere between the two, but this is very subjective and depends much upon one's personal hearing.
I know for mine that this is not the same as many other people's since I have more sensitivity to phase but possibly less to distortion (there is usually a trade off in these things) in the same way that my night vision is very good (2Gen+) but my colour is not so good as far as light levels go and I need brighter illumination to read etc.
I would think that technology types will be very similar however I do note that the IRFP150 has lower distortion by 0.1% or more than a IRFP140 and this is certainly audible to the trained/sensitive ear.
I used the MRF148's to illustrate that it was well worth while in experimenting with different mosfet types and bias levels. I would have to build a proper stereo amp for the living room to drive my main speakers to be able to give any reasonable comments as I don't think my little mono setup is really adequate for this.
And my 8 ohm load is (fortunately perhaps) very boring to listen to 🙂
Close matching of the fets should help a lot, and the 2SJ49s when biased correctly for the type should be good.
Hope this helps.
Best wishes,
Susan.
Hi peranders,
Thank you for the post.
I do now notice 🙂
Thanks.
I have WINaudioMLS...
http://www.dr-jordan-design.de/Winaudiomls.htm
... which I am setting up but I am having to make up buffers and test probes as the soundcards arn't too happy with 100 volts plus on their inputs 🙁
==========
I now have to go off for the day so will reply to other posts this evening.
... and I have some interesting news to share 🙂
I thank everyone who is following this thread for their continued interest and appreciate all your positive contributions to the discussion.
Best wishes,
Susan.
Thank you for the post.
peranders said:
I do now notice 🙂
Thanks.
I have WINaudioMLS...
http://www.dr-jordan-design.de/Winaudiomls.htm
... which I am setting up but I am having to make up buffers and test probes as the soundcards arn't too happy with 100 volts plus on their inputs 🙁
==========
I now have to go off for the day so will reply to other posts this evening.
... and I have some interesting news to share 🙂
I thank everyone who is following this thread for their continued interest and appreciate all your positive contributions to the discussion.
Best wishes,
Susan.
Commentable Experienced Thoughts
Hi SUSAN-PARKER MIEE,
I think I can put some words here on the sound of ur amp, which i have built a few days ago.
The Sound is more like a Valvetype besides it also contains a little solid state phenomena, but the Pleasing ODD harmonics are very much delightful to hear at 250WRMS with 18"low Frequency drivers and CTS PIEZO HORNS connected all the time.
The Highs are fully laden with Crispy and sheer detail, while the mids are somewhat mild again thanX to Transformer coupling, and the Bass is as deep as BLACK HOLE which consumes the senses of the hearing processes.
Thats What ur amp sound like.
In Simple Words It has an Image for a sound.
With Harmonic Regards
Workhorse Technologies.
Hi SUSAN-PARKER MIEE,
I think I can put some words here on the sound of ur amp, which i have built a few days ago.
The Sound is more like a Valvetype besides it also contains a little solid state phenomena, but the Pleasing ODD harmonics are very much delightful to hear at 250WRMS with 18"low Frequency drivers and CTS PIEZO HORNS connected all the time.
The Highs are fully laden with Crispy and sheer detail, while the mids are somewhat mild again thanX to Transformer coupling, and the Bass is as deep as BLACK HOLE which consumes the senses of the hearing processes.
Thats What ur amp sound like.
In Simple Words It has an Image for a sound.
With Harmonic Regards
Workhorse Technologies.
Re: Commentable Experienced Thoughts
Dear Amp_Man_1,
I'd like to gently suggest that you might wish to change out your piezo tweeters in favor of some other sort of tweeter? Piezo drivers generally have significantly higher levels of inherent distortion built into the design than one might like...
_-_-bear
amp_man_1 said:
Dear Amp_Man_1,
I'd like to gently suggest that you might wish to change out your piezo tweeters in favor of some other sort of tweeter? Piezo drivers generally have significantly higher levels of inherent distortion built into the design than one might like...
_-_-bear
similar design & transformers in b2 spice
Hi Susan,
I have just read through this thread with great interest and anticipation – This is just the kind of amp that appeals to my luddite tendencies.
I did not notice yet if you had an answer Sowter on the o/p transformers. I think would like the bi-filar version. As I would probably use them as chokes. Mind you the toroids also sound interesting. I wonder if anyone makes Bi Filar wound toroids these days.
B2SPICE...
I have been modeling an amp with some similar features for a year or two in b2spice. I always manage coupled chokes and transformers by using inductive coupling – it’s a bit hit and miss as you have to ajust the inductance to effectively change the number of windings. Also leaving the inductive coupling at 100% can cause problems... as can perfect symetry – almost perfect works OK !
Here is one version of my design – not yet built cos I got stuck on the chokes !
I will be very interested to try both your and my designs using as similar components as possible to see what audible effect the dreaded feedback has !!! As you can see this version has heavy feedback but I have simulated versions with source degeneration and higher open loop gain
Great thread....🙂
thanks
mike
Hi Susan,
I have just read through this thread with great interest and anticipation – This is just the kind of amp that appeals to my luddite tendencies.
I did not notice yet if you had an answer Sowter on the o/p transformers. I think would like the bi-filar version. As I would probably use them as chokes. Mind you the toroids also sound interesting. I wonder if anyone makes Bi Filar wound toroids these days.
B2SPICE...
I have been modeling an amp with some similar features for a year or two in b2spice. I always manage coupled chokes and transformers by using inductive coupling – it’s a bit hit and miss as you have to ajust the inductance to effectively change the number of windings. Also leaving the inductive coupling at 100% can cause problems... as can perfect symetry – almost perfect works OK !
Here is one version of my design – not yet built cos I got stuck on the chokes !
I will be very interested to try both your and my designs using as similar components as possible to see what audible effect the dreaded feedback has !!! As you can see this version has heavy feedback but I have simulated versions with source degeneration and higher open loop gain
Great thread....🙂
thanks
mike
Attachments
Re: Re: Commentable Experienced Thoughts
Generally because they are most off not implemented very well... the piezo in the Phy-HP 12" coax works quite well
dave
bear said:
Generally because they are most off not implemented very well... the piezo in the Phy-HP 12" coax works quite well
dave
WARNING!!!
DO NOT OMIT THE GATE-SOURCE VOLTAGE PROTECTION!!!!!
I Played realy loud and all of a sudden it was quiet. Both fets was fully open and it had 28 ampere current running through the transformer....
No good.
Me: 😡
😕 
😡
allrightythen....I was playing Ricky Martin and my amp developed some kind of allergy.🙂devilr: )
DO NOT OMIT THE GATE-SOURCE VOLTAGE PROTECTION!!!!!
I Played realy loud and all of a sudden it was quiet. Both fets was fully open and it had 28 ampere current running through the transformer....
No good.
Me: 😡
😕 😡 allrightythen....I was playing Ricky Martin and my amp developed some kind of allergy.🙂devilr: )
Amp Changes 2 - running
Hi,
1) today a new input stage transformer Tr1 is arrived: 230V, 2x12V 30VA.
2) So i change the Tr2 too, i use now two single 100VA, 25V/4A one for each Mosfet IRF 530N.
3) Thecurrent trought the mosfet is now a little bit higher.
The Bias-offset of my current control is 140mV and
across the 25V winding from Tra/Tr2b 47mV.
See:
Now is sounds very good, i use some two-way loudspeaker with 91dB for my firs reallive tests.
greetings from germany.
- uwe
http://bauteile-fuer-die-elektronik.de/projekte/Zeus/
Hi,
1) today a new input stage transformer Tr1 is arrived: 230V, 2x12V 30VA.
2) So i change the Tr2 too, i use now two single 100VA, 25V/4A one for each Mosfet IRF 530N.
3) Thecurrent trought the mosfet is now a little bit higher.
The Bias-offset of my current control is 140mV and
across the 25V winding from Tra/Tr2b 47mV.
See:
An externally hosted image should be here but it was not working when we last tested it.
Now is sounds very good, i use some two-way loudspeaker with 91dB for my firs reallive tests.
greetings from germany.
- uwe
http://bauteile-fuer-die-elektronik.de/projekte/Zeus/
Re: WARNING!!!
😀
Susan has integrated a protection (undocumentated) against Ricky Martin, Brittney Spears and a few more artists. The amp will self destruct if you play uncertified artists.Circlomanen said:Me: 😡
allrightythen....I was playing Ricky Martin and my amp developed some kind of allergy.🙂devilr: )
😀