Yes, you can replace the 1k resistor at the speaker output with 220R.
Yes, connect the 10k gate resistor to V- of a V- power supply.
Also note that with a V- power supply, the 10mF output capacitor should have the negative terminal connected to the SIT and the positive terminal connected to the speaker.
Yes, connect the 10k gate resistor to V- of a V- power supply.
Also note that with a V- power supply, the 10mF output capacitor should have the negative terminal connected to the SIT and the positive terminal connected to the speaker.
3: R5 output (220 Ohms or 1K/4W), less of the HP and Drain connected to GND (+).
Thank you, Ben.
Thank you, Ben.
Hello Ben Mah,
Ok the - C2(10000μF) must be connected to the source of the SIT,the + C2 (10000μF) at the resistance of 1K/4W and the HP , the Drain of the SIT to GND.
Ok the - C2(10000μF) must be connected to the source of the SIT,the + C2 (10000μF) at the resistance of 1K/4W and the HP , the Drain of the SIT to GND.
Good evening, gentlemen,
If a negative power supply is chosen, can we use a MEAN WELL HRP-600N3-36, the least of it connected to the -V circuit and the + of the power supply to the GND circuit?
Thanking you in advance.
Toto34.
If a negative power supply is chosen, can we use a MEAN WELL HRP-600N3-36, the least of it connected to the -V circuit and the + of the power supply to the GND circuit?
Thanking you in advance.
Toto34.
That is a bit too much for to247 devices because of their limited dissipation capability.
If you want to use a 36v ps you will need to lower the bias which is very important for an output stage like the Mofo so I don’t recommend it. A better approach would be to use sot227 or pucks as we call them here which are more expensive but because they can take a higher bias you will get better performance.
Obviously for this job you will need bigger heatsinks.
If you want to use a 36v ps you will need to lower the bias which is very important for an output stage like the Mofo so I don’t recommend it. A better approach would be to use sot227 or pucks as we call them here which are more expensive but because they can take a higher bias you will get better performance.
Obviously for this job you will need bigger heatsinks.
If you are using the THF-51S in the circuit as you had mentioned in post #534, the 36VDC of the Mean Well supply should not be a problem. I run a 37.5VDC power supply with my 193V loaded 2SK180 follower at 3.0A with no problem, and the 2SK180 is rated at only 300W whereas the THF-51S is rated at 400W dissipation. As schultzsch mentioned you need heatsinks that can handle the heat.
I have tested my 2SK180 amp and at 2.5A and it is good for about 25W output at 8 Ohm, and at 3.0A it is good for about 35W.
Good evening, Schultzsch,
I use THF-51S which are capable of supporting 89 Watts (Vds 35.5V with 2,5 Amps) as in the 25W Single Ended Hammond 193V Choke Loaded 2SK180 The Amp from Ben Mah.
Can be used with the MEAN WELL HRP-600N3-36 for ra7 schematics (TDV) for use with the Amp Version schematic (negative power supply).
The MEAN WELL HRP-600N3-36 output V- connected to the amp’s V- circuit and the MEAN WELL HRP-600N3-36 V+ connected to the amp’s GND?
I use THF-51S which are capable of supporting 89 Watts (Vds 35.5V with 2,5 Amps) as in the 25W Single Ended Hammond 193V Choke Loaded 2SK180 The Amp from Ben Mah.
Can be used with the MEAN WELL HRP-600N3-36 for ra7 schematics (TDV) for use with the Amp Version schematic (negative power supply).
The MEAN WELL HRP-600N3-36 output V- connected to the amp’s V- circuit and the MEAN WELL HRP-600N3-36 V+ connected to the amp’s GND?
Good evening Ben Mah
Our posts crossed 'yes I have big heatsinks capable of supporting 200W and thank you for your patience to all of you and answer my questions.
Thank you.
Our posts crossed 'yes I have big heatsinks capable of supporting 200W and thank you for your patience to all of you and answer my questions.
Thank you.
I might have missed his bias, but what would be too hight with the his TFA-51s @ 36V?
I had not seen the last posts before posting, I was also thinking about Ben Mah's report of using up to 3A with that voltage and the TFH-51S.
Regarding voltage, the jump from 27 to 36V was found to be positive. A few times here and in the Fokin thread some have asked about using a higher voltage (45V) but I haven't found any report of someone who has tried it. I wonder if ramping the voltage up to that point would bring some benefits and I might choose my caps with that in mind.
@1.8A the increase in voltage from 27 to 37 brought H2 below H3 (@1W). OTOH Ben Mah's distortion measurements @3A show H3 below H2 up to 25W.
Regarding voltage, the jump from 27 to 36V was found to be positive. A few times here and in the Fokin thread some have asked about using a higher voltage (45V) but I haven't found any report of someone who has tried it. I wonder if ramping the voltage up to that point would bring some benefits and I might choose my caps with that in mind.
@1.8A the increase in voltage from 27 to 37 brought H2 below H3 (@1W). OTOH Ben Mah's distortion measurements @3A show H3 below H2 up to 25W.
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If you are thinking about 36V you would probably be buying 50V capacitors, and those would work with 45V.
I haven't tried 45V but I would guess that to get the most out of the higher voltage you may need to go higher current too to achieve higher power output. An easy way to investigate that is with LTSpice.
Of course the choke would need to be able to handle the current, the heat sink would need to be able to handle the dissipation, and the SIT dissipation would need to be kept within reason.
I haven't tried 45V but I would guess that to get the most out of the higher voltage you may need to go higher current too to achieve higher power output. An easy way to investigate that is with LTSpice.
Of course the choke would need to be able to handle the current, the heat sink would need to be able to handle the dissipation, and the SIT dissipation would need to be kept within reason.
Ups, sorry for the confusion, I wanted to say big Tokins.
To have a sit amp that is h2 dominant on the entire power bandwidth you need to increase vds and bias proportionally else it will become h3 dominant from a certain point if you increase only vds.
If you increase only the vds without the bias you will get better performance(lower thd) but the amp won’t be h2 dominant on the entire power bandwidth.
At 45vds it is possible that you won’t be able to bias it high enough(because reaching thermal dissipation limit) to have it h2 dominant on the entire power bandwidth.
Hello Ben Mah,
I have 193V/3A this should work, the capacitors of 10000μF are 80Volts polarized.
Good day or night to all of you.
Toto34.
I have 193V/3A this should work, the capacitors of 10000μF are 80Volts polarized.
Good day or night to all of you.
Toto34.
Hello Ben Mah ,
The heatsinks make 200X300X83 for smaller 2 pieces
And 400X300X83 for larger 2 pieces
I think the smaller ones are OK for 100 Watts 400 Watts for the big ones?
The heatsinks make 200X300X83 for smaller 2 pieces
And 400X300X83 for larger 2 pieces
I think the smaller ones are OK for 100 Watts 400 Watts for the big ones?