sure 6AS7 without that CCS is rather pointless in this circuit, but let's say 6n6p should do the job on its own.
i would love the simulation please,...if you could do one with ecc99 and 45 that would be fantastic.
pleeese.
thanx.
OK, here we go...
Remember, this is an experiment. Just a *computer simulation*. It is not tested at all. No guarantees. Please anyone with more experience and/or knowledge, feel free to criticize, make suggestions, throw rotten vegetables at me, whatever.
LTspice simulated 45 line stage with 10M45S CCS in the plate, +200VDC plate supply.
It does not show power supply, biasing arrangement, volume control/switching, or any other ancillary circuits that will be necessary for usage.
LTspice says it will perform very well indeed. With 1kHz input, 1V RMS output into 10k ohm load, THD is predicted to be below 0.05%, and just about all second harmonic.
I hope it helps.
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Remember, this is an experiment. Just a *computer simulation*. It is not tested at all. No guarantees. Please anyone with more experience and/or knowledge, feel free to criticize, make suggestions, throw rotten vegetables at me, whatever.
LTspice simulated 45 line stage with 10M45S CCS in the plate, +200VDC plate supply.
It does not show power supply, biasing arrangement, volume control/switching, or any other ancillary circuits that will be necessary for usage.
LTspice says it will perform very well indeed. With 1kHz input, 1V RMS output into 10k ohm load, THD is predicted to be below 0.05%, and just about all second harmonic.
I hope it helps.
--
Attachments
thank you so much!, i will give it a try,
do you think that you could do one without CCS and add ecc99 on top of 45
? please.
Using an ECC99 woud be just using a tube acting as the constant current source in the plate of the 45, instead of the 10M45S MOSFET. It will do a worse job, but still might be 'good enough'.
You will have to raise the heater supply for ECC99 a minimum of +150V (above ground), or the ECC99 will be destroyed over time. Not difficult to do, but will have to be done.
Is that what you want?
You will have to raise the heater supply for ECC99 a minimum of +150V (above ground), or the ECC99 will be destroyed over time. Not difficult to do, but will have to be done.
Is that what you want?
Also, experimental. High voltages can maim or kill. Use at your own risk.
I had to use a 6N6P model instead of ECC99, because I don't have an ECC99 model. 6N6P is very close, though. Basically a Russian version of the ECC99.
You will need to raise the heater supply of the ECC99 up to +200V or thereabouts. The heater needs to be within about +/-50V of the tubes' cathodes.
There will be more high wattage resistors needed for this circuit. This and the tubes running with fairly high plate currents will need to dissipate a lot of heat.
The Coleman Regulator is best used with filamentary bias, but that probably will not be possible with a 45, because you're looking at 17V grid-to-cathode at 35mA plate current, which means the bias resistor will end up needing to be one big wattage part. It will be large and it will run hot.
Again, this is just a computer simulation. Not tested, no guarantees.
Simulated performance looks good. THD is only slightly higher than from the version with 10M45S in the 45 plate. Gain is a little lower, because the paralleled 6N6P has much lower gain than the 10M45S.
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I had to use a 6N6P model instead of ECC99, because I don't have an ECC99 model. 6N6P is very close, though. Basically a Russian version of the ECC99.
You will need to raise the heater supply of the ECC99 up to +200V or thereabouts. The heater needs to be within about +/-50V of the tubes' cathodes.
There will be more high wattage resistors needed for this circuit. This and the tubes running with fairly high plate currents will need to dissipate a lot of heat.
The Coleman Regulator is best used with filamentary bias, but that probably will not be possible with a 45, because you're looking at 17V grid-to-cathode at 35mA plate current, which means the bias resistor will end up needing to be one big wattage part. It will be large and it will run hot.
Again, this is just a computer simulation. Not tested, no guarantees.
Simulated performance looks good. THD is only slightly higher than from the version with 10M45S in the 45 plate. Gain is a little lower, because the paralleled 6N6P has much lower gain than the 10M45S.
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Attachments
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I'm aware of the heater to cathode voltage but hats easy 2 resistors and a cap,
i was thinking to use perhaps just one half of ecc99 over 45 instead of both,....could you please simulate it?.
i would build both versions ccs and triode mu to compare what is good enough. 🙂
thank you for your time, and fantastic help.
That's pretty easy.
1) Remove U3 (second half of 6N6P).
Plate dissipation of the single 6N6P will be around its maximum allowable (about 3W). It will work, but you'll be replacing tubes more often. Otherwise it should work almost as well as the parallel-6N6P version.
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I managed to track down my post from the Tram 2 thread, which suggests that the designer described it as a super mu follower
DHT OTL Linestage - Tram 2
The choke assisted mu stage was presented by Alan Kimmel in Vacuum Tube Valley 20, and appears to be the inspiration for placing the CCS in the Tram 2 mu stage
best of luck
fantastic, i may try with e182, as far as i remember plate dissipation is 4W.
will give it a go will let you know for sure.
many thanx for your time.
best.
have a great day! 🙂
i was thinking of what you said when 45 used and 17v grid to the cathode at 35mA and that's a big current and resistor will have to be quite WWW, i will try the same but with 101d tube that i have on hand as well, I think the plate current will be around 3mA at the same grid to cathode voltage. can i try it in exactly the same simulation instead 45? , i will obviously have to change DHT's resistor to a bigger value.
Late to the party, I wrote this yesterday but got called away before hitting the post button. It might as well be thrown into the hat as well .
You could take a look at Gary Pimm's version. On this page the CCS with MU output is the Rev 5 hybrid. You can see where he used it on his 300B amp , linked farther down the page.
You could take a look at Gary Pimm's version. On this page the CCS with MU output is the Rev 5 hybrid. You can see where he used it on his 300B amp , linked farther down the page.