Keypunch,
None of them are thermally coupled with the driver heatsink... just those MJE's 😀
In all my tests I used a fan at driver heatsink. It stays just a little warm.
Quasi,
Yes, the small heatsink is being held up by the transistors only. And it's held very good.
I will try grounding the main heatsink...
The material for insulators i don't know how it's named... but it's that standard flexible one with glass fibre.
None of them are thermally coupled with the driver heatsink... just those MJE's 😀
In all my tests I used a fan at driver heatsink. It stays just a little warm.
Quasi,
Yes, the small heatsink is being held up by the transistors only. And it's held very good.
I will try grounding the main heatsink...
The material for insulators i don't know how it's named... but it's that standard flexible one with glass fibre.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Hi,
check that each of the MJs are really electrically isolated from the common heatsink.
Check that each of the outputs is also isolated.
That glass reinforced isolator looks very thick. Is it an effective conductor of heat?
Have you used the same thick isolator for the output FETs?
check that each of the MJs are really electrically isolated from the common heatsink.
Check that each of the outputs is also isolated.
That glass reinforced isolator looks very thick. Is it an effective conductor of heat?
Have you used the same thick isolator for the output FETs?
you need to add 100uf across the 0.1's on the driver side!
i cannot see enough decupling?
andy
i cannot see enough decupling?
andy
Hi,
I never turn on an amp until i check that all transistors are insulated from heatsinks ! 😱
Yes, I used the same isolator for FET's and for all. And it's special for this job ... i don't have any doubt.
I never turn on an amp until i check that all transistors are insulated from heatsinks ! 😱
Yes, I used the same isolator for FET's and for all. And it's special for this job ... i don't have any doubt.
Re: Post #2340
Hi Quasi,
Thanks. I know the hv reg nmos amp.pdf was very early on in your design stage of the amplifier. My interest in the hv reg nmos amp.pdf is I have always wanted to isolate the output driver stage PSU from the rest of the amplifier. Many seem to feel doing so adds clarity, width of soundstage, and/or increased resolution to any amplifier. I am also considering other regulated PSU R-C based designs, sometimes misnames as snubberized designs when the bridge is not snubbed or RC'ed. It is not my intention to have a seperate front end PSU to run at a higher voltage to offset the typical 10VDC rail difference between the output driver stage and front end stages.
Glad you found the links useful. It does takes extra effort. When the effort does take alot of extra time it is usually due to searching the thread, which also means reading posts, sometimes many, to find the information for the links posted. My last post for Marus took alot of time to do as with the added twist I had to find an alternate source for the images so I could link to the specific image as a reference, andscanning the thread postings until not quite half way through the thread.
The question I asked re the values for R5/R6 I have been meaning to ask for over a year and just keep forgetting. I have had the PDF of the circuit for two years.
Thanks again for your time and effort. I am still behind in some questions to ask or followups. I am also way behind in updating the project site I had that has had all kinds of site management bugs and a tech support staff that cannot understand english. I have a possible alternate site I can use, but it will take me time to update what I need to and then create it. Time I do not see having for a while yet. I like your site very much, simple and efficient. I am not a fan of frames, but I will live 😉
Regards,
John L. Males
Willowdale, Ontario
Canada
16 September 2007 12:24
Official Quasi Thread Researcher
quasi said:
Hi Quasi,
Thanks. I know the hv reg nmos amp.pdf was very early on in your design stage of the amplifier. My interest in the hv reg nmos amp.pdf is I have always wanted to isolate the output driver stage PSU from the rest of the amplifier. Many seem to feel doing so adds clarity, width of soundstage, and/or increased resolution to any amplifier. I am also considering other regulated PSU R-C based designs, sometimes misnames as snubberized designs when the bridge is not snubbed or RC'ed. It is not my intention to have a seperate front end PSU to run at a higher voltage to offset the typical 10VDC rail difference between the output driver stage and front end stages.
Glad you found the links useful. It does takes extra effort. When the effort does take alot of extra time it is usually due to searching the thread, which also means reading posts, sometimes many, to find the information for the links posted. My last post for Marus took alot of time to do as with the added twist I had to find an alternate source for the images so I could link to the specific image as a reference, andscanning the thread postings until not quite half way through the thread.
The question I asked re the values for R5/R6 I have been meaning to ask for over a year and just keep forgetting. I have had the PDF of the circuit for two years.
Thanks again for your time and effort. I am still behind in some questions to ask or followups. I am also way behind in updating the project site I had that has had all kinds of site management bugs and a tech support staff that cannot understand english. I have a possible alternate site I can use, but it will take me time to update what I need to and then create it. Time I do not see having for a while yet. I like your site very much, simple and efficient. I am not a fan of frames, but I will live 😉
Regards,
John L. Males
Willowdale, Ontario
Canada
16 September 2007 12:24
Official Quasi Thread Researcher
Finally some good news !
😀 😀 😀
I found the GUILTY one. This is it :
I change all components to original Quasi schematic values, remove L1, ground main heatsink and driver heatsink and the amp finally works on +/- 80V rails ! 😀
But the problem it's not over yet !
The amp MUST have a Low Pass Filter on his output ....
Quasi, as you can see (from the picture), i not made the inductor like you said : 10 turns x 3 layers 🙁 .... just 20 turns x 1 layer ... but you said " The final value of this inductor is not critical at all so you can vary this to use what is available to you. "
I will try to make it exactly like you did.
😀 😀 😀
I found the GUILTY one. This is it :
An externally hosted image should be here but it was not working when we last tested it.
I change all components to original Quasi schematic values, remove L1, ground main heatsink and driver heatsink and the amp finally works on +/- 80V rails ! 😀
But the problem it's not over yet !
The amp MUST have a Low Pass Filter on his output ....
Quasi, as you can see (from the picture), i not made the inductor like you said : 10 turns x 3 layers 🙁 .... just 20 turns x 1 layer ... but you said " The final value of this inductor is not critical at all so you can vary this to use what is available to you. "
I will try to make it exactly like you did.
AndrewT said:
You're talking about DC input resistance.
Input impedance is calculated/measured on a fixed AC frequency, say 1kHz.
At 1kHz the input impedance of Nmos350 is 160+1k+480k//33k=32k (1u, 1k, 390p, 33k)
But you're right about that my previuos post about 30k wasn't accurate.
Hi DZ,
your about covered the accuracy.
I was trying to get Marus to recognise where his values came from.
your about covered the accuracy.
I was trying to get Marus to recognise where his values came from.
Toroid Reworking
Hi,
I have been thinking of taking a 39.8-0-39.8 650VA toriod and turning it into a two seperate 30V secondaries 800VA and two 37V secondaries 74VA. The primary would be for 115V. I have looked high and low on internet to find out what guage and number of windings to use. I have also searched diyAudio, but with no success. I have tried different combinations of search keywords as part of the search process. If anyone knows how I can accomplish this goal or can point me to links to educate me it would be much appreciated. I suspect I will need to strip all way back to the core.
Regards,
John L. Males
Willowdale, Ontario
Canada
20 September 2007 21:50
Official Quasi Thread Researcher
Hi,
I have been thinking of taking a 39.8-0-39.8 650VA toriod and turning it into a two seperate 30V secondaries 800VA and two 37V secondaries 74VA. The primary would be for 115V. I have looked high and low on internet to find out what guage and number of windings to use. I have also searched diyAudio, but with no success. I have tried different combinations of search keywords as part of the search process. If anyone knows how I can accomplish this goal or can point me to links to educate me it would be much appreciated. I suspect I will need to strip all way back to the core.
Regards,
John L. Males
Willowdale, Ontario
Canada
20 September 2007 21:50
Official Quasi Thread Researcher
John,
You should wind 10 turns of enamelled wire ( magnet wire ) on the existing transformer and switch it on ( no load ). Measure the voltage (V ) across the 10 turns ( make sure it is a 'full' 10 turns).
Divide V by 10 . You get volts per turn being used on your transformer . Now you can divide the volts you want with the volts per turn you got and you will get the number of turns you require.
Note that the VA rating of the transformer will remain the same and you cannot increase that. The wire guage can be obtained from the wire guage table . Or measure what is on the transformer and scale it up or down depending on what you want.
I guess your original primary is 110 V already ? In that case you can leave it as it is and just wind the secondary ( if its on top ).
You have so many options that I will not go into them all.
You can easily add a 75 Va winding as it is. You will need a very small dia enamelled wire for this. On a 650 VA trafo it shouldn't make too much difference as your main windings will not be using their full rating continuously (?).
Cheers.
You should wind 10 turns of enamelled wire ( magnet wire ) on the existing transformer and switch it on ( no load ). Measure the voltage (V ) across the 10 turns ( make sure it is a 'full' 10 turns).
Divide V by 10 . You get volts per turn being used on your transformer . Now you can divide the volts you want with the volts per turn you got and you will get the number of turns you require.
Note that the VA rating of the transformer will remain the same and you cannot increase that. The wire guage can be obtained from the wire guage table . Or measure what is on the transformer and scale it up or down depending on what you want.
I guess your original primary is 110 V already ? In that case you can leave it as it is and just wind the secondary ( if its on top ).
You have so many options that I will not go into them all.
You can easily add a 75 Va winding as it is. You will need a very small dia enamelled wire for this. On a 650 VA trafo it shouldn't make too much difference as your main windings will not be using their full rating continuously (?).
Cheers.
Re: Toroid Reworking
Firstly,
do not strip it back to the core.
The most critical part considering safety is the core and it's insulation.
I read in DIYaudio that the copper secondary normally carries between 1.6A and 3.1A per sqmm. 16swg~=1.6mm diameter.
I adopt the current cheaper standard of 3.1A/sqmm. This results in 6.2Aac from 16guage. Your American guages are different from SWG, (BG, AWG etc).
Take those same 16swg turns and wind on Xturns to give 10V opencircuit. You now have a winding capable of a maximum of 6.2*10/(1+regulation)~=62/1.07~=58VA. The maximum DC current from this winding after rectifying and smoothing with a capacitor input filter will be about 3.1Adc @ approximately 13Vdc.
You can fit as many different windings on the transformer as you have space for. The total VA of all the windings can be far in excess of the VA rating of the transformer primary and core. But the total continuous power drawn from all the secondaries should not exceed the transformer rating. Similarly the maximum continuous power drawn from any secondary should not exceed it's VA rating.
All this is in DIYaudio, but I'll bet I cannot find it either. It would need to be a big bet to make me try.
Hi,keypunch said:
Firstly,
do not strip it back to the core.
The most critical part considering safety is the core and it's insulation.
I read in DIYaudio that the copper secondary normally carries between 1.6A and 3.1A per sqmm. 16swg~=1.6mm diameter.
I adopt the current cheaper standard of 3.1A/sqmm. This results in 6.2Aac from 16guage. Your American guages are different from SWG, (BG, AWG etc).
Take those same 16swg turns and wind on Xturns to give 10V opencircuit. You now have a winding capable of a maximum of 6.2*10/(1+regulation)~=62/1.07~=58VA. The maximum DC current from this winding after rectifying and smoothing with a capacitor input filter will be about 3.1Adc @ approximately 13Vdc.
You can fit as many different windings on the transformer as you have space for. The total VA of all the windings can be far in excess of the VA rating of the transformer primary and core. But the total continuous power drawn from all the secondaries should not exceed the transformer rating. Similarly the maximum continuous power drawn from any secondary should not exceed it's VA rating.
All this is in DIYaudio, but I'll bet I cannot find it either. It would need to be a big bet to make me try.
Re: Toroid Reworking
Ashok,
Thanks so much for your reply. My comments, answers and questions are below:
Excellent.
Does the actual core ring fix the VA? If I want the main secondary, in my case 30-0 X2, can the VA still remain at 650 for the 30-0 X 2
110V is the primary. It is not a 110/220 or 115/230 or 120/240 dual primary.
You raise an interesting point to wind atop the existing windings.
I like options. Do you have any of the so many you might want to suggest?
I suppose for the desired 30-0 X 2 secondaries I could wind those atop to be the 650 VA windings and use the existing secondaries of 39.8 for the 75VA requirement. Could I use electrical tape to insulate the existing windings before I place the two additional secondaries of 30-0 I wish to add?
Correct, the toroid will not be running at full VA rating continously.
Andrew,
Thanks so much for your reply. My comments and questions below:
Is it safe to wrap electrical tape over the existing windings before add each of the additional secondaries? I assume when adding two 30-0 secondaries I need to wrap electrical tape between each of the added windings? I sense maybe it is better for me to leave the existing 39.8-0-39.8 secondary and add the two 30-0V desired secondaries to run at the 650VA rating and use the existing 39.8-0-39.8 secondary for the 75VA secondary?
Excellent. I did not even find the mm**2 wire guage current carrying rating in my searching. Thanks for the formula. I will likely adopt towards the 1.6A per mm**2.
Understood. Is the toroid core the determining factor to max VA rating? Maybe I will want to add four 30-0V secondaries. If there is is not enough room on the core I may then elect to remove the existing 39.8-0-39.8V secondary to allow the two or four 30-0V secondaries for 650VA and two or four 75VA windings for 40V.
No need for me to place a big bet. I am sure this infor and this sort of question and discussion is on diyAudio. I did search directly on diyAudio with no luck finding any such discusions I was sure existed on diyAudio. As commented by myself and others before the search function of diyAudio is limited. Hence one often has my fruitful success using search engines that will find links on diyAudio as well as non-diyAudio links.
Thanks again Andrew.
To Anyone,
One more question if I may. I have some toroids that have some sort of epoxy filling the centre hole of the toroid. Could this centre epoxy be removed easily so I could add some windings to these toroids? This of course assumes it makes sense for other reasons to consider removing this centre hole expoxy.
Regards,
John L. Males
Willowdale, Ontario
Canada
21 September 2007 22:15 - 22 September 2007 00:14
Official Quasi Thread Researcher
ashok said:
Ashok,
Thanks so much for your reply. My comments, answers and questions are below:
Excellent.
Does the actual core ring fix the VA? If I want the main secondary, in my case 30-0 X2, can the VA still remain at 650 for the 30-0 X 2
110V is the primary. It is not a 110/220 or 115/230 or 120/240 dual primary.
You raise an interesting point to wind atop the existing windings.
I like options. Do you have any of the so many you might want to suggest?
I suppose for the desired 30-0 X 2 secondaries I could wind those atop to be the 650 VA windings and use the existing secondaries of 39.8 for the 75VA requirement. Could I use electrical tape to insulate the existing windings before I place the two additional secondaries of 30-0 I wish to add?
Correct, the toroid will not be running at full VA rating continously.
AndrewT said:
Andrew,
Thanks so much for your reply. My comments and questions below:
Is it safe to wrap electrical tape over the existing windings before add each of the additional secondaries? I assume when adding two 30-0 secondaries I need to wrap electrical tape between each of the added windings? I sense maybe it is better for me to leave the existing 39.8-0-39.8 secondary and add the two 30-0V desired secondaries to run at the 650VA rating and use the existing 39.8-0-39.8 secondary for the 75VA secondary?
Excellent. I did not even find the mm**2 wire guage current carrying rating in my searching. Thanks for the formula. I will likely adopt towards the 1.6A per mm**2.
Understood. Is the toroid core the determining factor to max VA rating? Maybe I will want to add four 30-0V secondaries. If there is is not enough room on the core I may then elect to remove the existing 39.8-0-39.8V secondary to allow the two or four 30-0V secondaries for 650VA and two or four 75VA windings for 40V.
No need for me to place a big bet. I am sure this infor and this sort of question and discussion is on diyAudio. I did search directly on diyAudio with no luck finding any such discusions I was sure existed on diyAudio. As commented by myself and others before the search function of diyAudio is limited. Hence one often has my fruitful success using search engines that will find links on diyAudio as well as non-diyAudio links.
Thanks again Andrew.
To Anyone,
One more question if I may. I have some toroids that have some sort of epoxy filling the centre hole of the toroid. Could this centre epoxy be removed easily so I could add some windings to these toroids? This of course assumes it makes sense for other reasons to consider removing this centre hole expoxy.
Regards,
John L. Males
Willowdale, Ontario
Canada
21 September 2007 22:15 - 22 September 2007 00:14
Official Quasi Thread Researcher
Hi Keypunch,
Yes, the actual core ring fix the VA. I'm not sure what formula is used on toroids ( i think it's the same) but at classical E+I cores it is : VA= core area^2. You can make any combination of current and voltage but the power is given by The Core
For isolation I use a thick paper hold it with electrical tape.
I just finished my 430W transformer for one Nmos350 amp 😀
Yes, the actual core ring fix the VA. I'm not sure what formula is used on toroids ( i think it's the same) but at classical E+I cores it is : VA= core area^2. You can make any combination of current and voltage but the power is given by The Core
For isolation I use a thick paper hold it with electrical tape.
I just finished my 430W transformer for one Nmos350 amp 😀
Hi John,
I used to have a transformer winding guide from long ago on cyclostyled sheets ( remember cyclostying ?) As they are falling apart I decided to put them on Word . This will take a few days . If you want I could email you a copy.
The core material ( determines max operating flux ) and cross
sectional area determines the max VA that the core can be used for. The basic operation is to take electrical energy , convert it to magnetic energy using the primary coils and then convert it back to electrical energy using the secondary coils. Hope the concept is clear. Larger core ... more VA can be passed through.
You can have any reasonable voltage and current combination as long as Volts x Amps does not exceed the VA rating of the core . There are losses etc but then we are simplifying the current situation. So 30 v x 2 is fine and you can have higher current flow than a 38.5 x2 coil. About 30% higher . This is if you wind a new secondary coil.
I mentioned 'options' because I do not know how your transformer is currently wound. Most have their secondary wound on top of the primary . You can see this if the wire is fairly thick. Primary wire will be much thinner.
Since you need a 110 volt primary and the transformer already has this , you can unwind just the seconday coils . How is that wound ? Bifilar or a series connected coil ? Often it is just a series connected coil. 39.8 volts followed by another 39.8 volt coil and the center is brought out ( 0 Volt ). You could count the number of turns you are unwinding .When you reach the 0 Volt tap , you have the number of turns that they have used , say N turns. Your new coil will need N*30/38.5 turns per coil . That is for each 0 to 30 volts coil.
The metal core will usually have a moulded plastic former on top of it . Better to be careful and not damage it if you intend unwinding all coils for some reason. You have a ready made primary coil and so there is no need to unwind that . Unless the primary voltage has to be different.
To check the wire guage , just wind 10 or 20 turns of a straightened section of wire on a pencil and measure the length of the winding. Divide by 10 or 20 and you will get the dia of the wire.
The other options I mentioned have to do with adding windings to bring down the secondary voltage though the windings will not be "optimal" for that core.
You can add an 'extra' ( single ) primary winding to reduce volts per turn of the primary coil and that will reduce the secondary voltage. Current rating of the coil will be determined by the original seconday coils but might not matter for most audio use.
So that means you will have 'another' primary coil wound on top of the existing coils and add a layer of insulation and then wind your 75VA coils again on top of this one.
The new 'primary coil' will be connected in series with the original primary coil . The secondary coils will remain the same ( now 30 - 0 - 30 volts ) and you have a new set of 75VA coils . These are less optimum windings but should be able to do what you want without major surgery or loosing too much power . Addng coils without dismantling the transformer must be an easy way out ?
To avoid the addition the winding of a 'primary' coil again , you can wind less number of turns for the seconday and connect this out of phase with the secondary to reduce the votage. This means less number of turns to wind. Wind two independent sets of 9.8 volt coils and connect each with one section of 39.8 volt coil ( in series) and it will drop the output voltage to 30 volts.
You need to use insulating mylar or leatheroid sheets between winding . You can use tape also but it should be able to withstand high temperatures. Normal PVC tapes are not recommended as they will soften ( and also get gooey ) very easily at say less than 100 deg C if there is a short circuit etc. I'm sure some good electrical tape will be available at a hardware store.
The 39.8 volt coils are meant for high current use and it would be meaningless if you use it for low current use. Their coils take up a large amount of space . You probably will not be able to wind another set of high current 30 - 0 - 30 volt coils over that due to space constraints.........maybe. I don't know how big your torroid is.
Better to wind two 9.8 volt coils and connect out of phase to get 30 volts. Then wind the low current 30 odd volt set of coils which will have enough space.
This might be getting a bit confusing .Want diagrams ?
Cheers,
Ashok.
I used to have a transformer winding guide from long ago on cyclostyled sheets ( remember cyclostying ?) As they are falling apart I decided to put them on Word . This will take a few days . If you want I could email you a copy.
The core material ( determines max operating flux ) and cross
sectional area determines the max VA that the core can be used for. The basic operation is to take electrical energy , convert it to magnetic energy using the primary coils and then convert it back to electrical energy using the secondary coils. Hope the concept is clear. Larger core ... more VA can be passed through.
You can have any reasonable voltage and current combination as long as Volts x Amps does not exceed the VA rating of the core . There are losses etc but then we are simplifying the current situation. So 30 v x 2 is fine and you can have higher current flow than a 38.5 x2 coil. About 30% higher . This is if you wind a new secondary coil.
I mentioned 'options' because I do not know how your transformer is currently wound. Most have their secondary wound on top of the primary . You can see this if the wire is fairly thick. Primary wire will be much thinner.
Since you need a 110 volt primary and the transformer already has this , you can unwind just the seconday coils . How is that wound ? Bifilar or a series connected coil ? Often it is just a series connected coil. 39.8 volts followed by another 39.8 volt coil and the center is brought out ( 0 Volt ). You could count the number of turns you are unwinding .When you reach the 0 Volt tap , you have the number of turns that they have used , say N turns. Your new coil will need N*30/38.5 turns per coil . That is for each 0 to 30 volts coil.
The metal core will usually have a moulded plastic former on top of it . Better to be careful and not damage it if you intend unwinding all coils for some reason. You have a ready made primary coil and so there is no need to unwind that . Unless the primary voltage has to be different.
To check the wire guage , just wind 10 or 20 turns of a straightened section of wire on a pencil and measure the length of the winding. Divide by 10 or 20 and you will get the dia of the wire.
The other options I mentioned have to do with adding windings to bring down the secondary voltage though the windings will not be "optimal" for that core.
You can add an 'extra' ( single ) primary winding to reduce volts per turn of the primary coil and that will reduce the secondary voltage. Current rating of the coil will be determined by the original seconday coils but might not matter for most audio use.
So that means you will have 'another' primary coil wound on top of the existing coils and add a layer of insulation and then wind your 75VA coils again on top of this one.
The new 'primary coil' will be connected in series with the original primary coil . The secondary coils will remain the same ( now 30 - 0 - 30 volts ) and you have a new set of 75VA coils . These are less optimum windings but should be able to do what you want without major surgery or loosing too much power . Addng coils without dismantling the transformer must be an easy way out ?
To avoid the addition the winding of a 'primary' coil again , you can wind less number of turns for the seconday and connect this out of phase with the secondary to reduce the votage. This means less number of turns to wind. Wind two independent sets of 9.8 volt coils and connect each with one section of 39.8 volt coil ( in series) and it will drop the output voltage to 30 volts.
You need to use insulating mylar or leatheroid sheets between winding . You can use tape also but it should be able to withstand high temperatures. Normal PVC tapes are not recommended as they will soften ( and also get gooey ) very easily at say less than 100 deg C if there is a short circuit etc. I'm sure some good electrical tape will be available at a hardware store.
The 39.8 volt coils are meant for high current use and it would be meaningless if you use it for low current use. Their coils take up a large amount of space . You probably will not be able to wind another set of high current 30 - 0 - 30 volt coils over that due to space constraints.........maybe. I don't know how big your torroid is.
Better to wind two 9.8 volt coils and connect out of phase to get 30 volts. Then wind the low current 30 odd volt set of coils which will have enough space.
This might be getting a bit confusing .Want diagrams ?
Cheers,
Ashok.
Hello Quasi
and guys at large
After a few months of doing the BJT brother of Quasi I finally finished
the Nmos 200 that I had thought to assemble just for comparison.
Unbelievable the way your designs are, they function at the first attempt there are no flaws or mishaps whatsoever, the results are
right there and sonically evident.
I built a few amplifiers in the past few years and for one reason or another I always had little problems to contend with, especially
dealing with complementary designs. Some were thrown out the
window either because they didn't work or the results were less
than optimal.
Not with your designs Quasi, they work at first attempt with the quality that surpasses by large all the others.
And even though I'm not a big fan of Mosfets I did this one just
for the sake of comparison. I used IRF 450, they were what I
had at hand, the quality is excellent, however there is no love like the first one and I really prefer the BJT version.
Happy to have embarqued in these projects and thanks for your
interest in the DIY community providing it with these true quality
designs.
and guys at large
After a few months of doing the BJT brother of Quasi I finally finished
the Nmos 200 that I had thought to assemble just for comparison.
Unbelievable the way your designs are, they function at the first attempt there are no flaws or mishaps whatsoever, the results are
right there and sonically evident.
I built a few amplifiers in the past few years and for one reason or another I always had little problems to contend with, especially
dealing with complementary designs. Some were thrown out the
window either because they didn't work or the results were less
than optimal.
Not with your designs Quasi, they work at first attempt with the quality that surpasses by large all the others.
And even though I'm not a big fan of Mosfets I did this one just
for the sake of comparison. I used IRF 450, they were what I
had at hand, the quality is excellent, however there is no love like the first one and I really prefer the BJT version.
Happy to have embarqued in these projects and thanks for your
interest in the DIY community providing it with these true quality
designs.
Hi Andrew T
This is a very interesting question....
And to be very honest with you I almost don't remember how the
Cyrus sound like because it has been almost a year that I don't
turn it on.
From what I remember it seems that the Cyrus is a very sweet amplifier being only comparable with the tube sound, whereas
the Quasi BJT has a little more impact as far as crescendos are
concerned. Both amplifiers pleased me a lot but that question
(thanks for it) gave me the urge of installing the Cyrus again in
my system. I'll do it soon and perhaps I'll get back to you.
This is a very interesting question....
And to be very honest with you I almost don't remember how the
Cyrus sound like because it has been almost a year that I don't
turn it on.
From what I remember it seems that the Cyrus is a very sweet amplifier being only comparable with the tube sound, whereas
the Quasi BJT has a little more impact as far as crescendos are
concerned. Both amplifiers pleased me a lot but that question
(thanks for it) gave me the urge of installing the Cyrus again in
my system. I'll do it soon and perhaps I'll get back to you.