I would set the pots to the lowest you can measure across the test points, but I suspect 200R is pretty close to that, so give it a go.
The source resistors are the big-a$$ resistors on the mosfet boards, they are connected to the sources of the mosfets, so they are very cleverly named source resistors.
Trust me, you are not the first to ask that.
The test point on the N and P boards are just a convenient place to measure across the source resistors when you are setting the bias.
The source resistors are the big-a$$ resistors on the mosfet boards, they are connected to the sources of the mosfets, so they are very cleverly named source resistors.
Trust me, you are not the first to ask that. The test point on the N and P boards are just a convenient place to measure across the source resistors when you are setting the bias.
Vince:
Link is used for balanced configurations. If you're building a single-ended amp, connect Link to Ground.
Your references to R5, R6 and R7 seem off to me. If you're referring to the resistors on the output boards (which are not designated R5, R6 or R7 on the v2.0 output boards), yes, the circuit calls for one 2.2k and a couple of 47R resistors per board (V2 only; for V3, use one 2.2k resistor per pair of output boards). However, you might want to use a higher value than 47R in the gatestopper position (100R to 120R seems to work well).
If you're referring to the front end board, R5 and R6 are 1k resistors. R7 is in parallel with R8 and both are 220R/3W for an effective resistance of 110R. I used a 110R/5W resistor across R7 and did not use R8.
Regards,
Scott
Link is used for balanced configurations. If you're building a single-ended amp, connect Link to Ground.
Your references to R5, R6 and R7 seem off to me. If you're referring to the resistors on the output boards (which are not designated R5, R6 or R7 on the v2.0 output boards), yes, the circuit calls for one 2.2k and a couple of 47R resistors per board (V2 only; for V3, use one 2.2k resistor per pair of output boards). However, you might want to use a higher value than 47R in the gatestopper position (100R to 120R seems to work well).
If you're referring to the front end board, R5 and R6 are 1k resistors. R7 is in parallel with R8 and both are 220R/3W for an effective resistance of 110R. I used a 110R/5W resistor across R7 and did not use R8.
Regards,
Scott
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no, acctualy you should never use more then 1pc 2.2K pr amp half regardless of number of output boards. 1 for N ch side. and 1 for P ch side. never more. (well. you can put in the resistor on all locations if you want, as long as you don't connect the thermistor that's going in series with it.)
Vince:
Mea culpa. It turns out I have the v3.0 F5T boards. Sorry for any confusion caused. But the advice remains the same: you need two 47R (or higher) gatestopper resistors per output board and one 2.2k resistor for each of the N and P sides of the circuit.
AudioSan:
I thought I had made the same point as you but, on reflection, your explanation is better because it is conceivable that someone would use more than 2 output boards per side in an F5T V3 build (e.g., when using 8 MOSFETs per side, one would need 4 N and 4 P output boards but still only one 2.2k resistor per side).
Regards,
Scott
Mea culpa. It turns out I have the v3.0 F5T boards. Sorry for any confusion caused. But the advice remains the same: you need two 47R (or higher) gatestopper resistors per output board and one 2.2k resistor for each of the N and P sides of the circuit.
AudioSan:
I thought I had made the same point as you but, on reflection, your explanation is better because it is conceivable that someone would use more than 2 output boards per side in an F5T V3 build (e.g., when using 8 MOSFETs per side, one would need 4 N and 4 P output boards but still only one 2.2k resistor per side).
Regards,
Scott
Vince - This thread was made with the old PCB, it may be helpful; http://www.diyaudio.com/forums/pass-labs/230247-building-f5-turbo-v2-progress.html
What do you guys think of this thermostat? Never used one before. Not seeing something exactly at 75 degrees C.
Mouser: 3L11-160 (Open on rise) 1 55 to 165 (°F), 68 to 74 (°C)
On a stereo build, is it OK to use on one heat sink? Using two transformers. Should I use one per transformer primary?
Do the thermostats need electrical isolation from the heat sink? Data sheet doesn't say.
I'm guess no, because anything impeding heat transfer would be bad.
Thanks,
Vince
Mouser: 3L11-160 (Open on rise) 1 55 to 165 (°F), 68 to 74 (°C)
On a stereo build, is it OK to use on one heat sink? Using two transformers. Should I use one per transformer primary?
Do the thermostats need electrical isolation from the heat sink? Data sheet doesn't say.
I'm guess no, because anything impeding heat transfer would be bad.
Thanks,
Vince
I am a happy owner of a F5 clone ... but always wants more.
I will continue this fantastic tutorial to build the amplifier (thanks 6l6) and I now have a couple of questions:
- This tutorial riding a f5T with cascode but uses a transformer to generate 32V, then why use cascode ?, preserves the life of jfet?
- My intention is to assemble a f5t v2 into two separate psu with each chassis (not a v3). I purchased two universal psu Diyaudio. What transformer and filter capacity is recommended for each left and right channel ?. I am not sure if the recommendation of 600VA is for each channel (1200VA total) or both together. In the latter case it would 300VA for each channel.
Thanks again for the help !. Excuse my English
I will continue this fantastic tutorial to build the amplifier (thanks 6l6) and I now have a couple of questions:
- This tutorial riding a f5T with cascode but uses a transformer to generate 32V, then why use cascode ?, preserves the life of jfet?
- My intention is to assemble a f5t v2 into two separate psu with each chassis (not a v3). I purchased two universal psu Diyaudio. What transformer and filter capacity is recommended for each left and right channel ?. I am not sure if the recommendation of 600VA is for each channel (1200VA total) or both together. In the latter case it would 300VA for each channel.
Thanks again for the help !. Excuse my English
To show how it is wired. And the cascode doesn't hurt anything at lower voltage.
Yes, 300VA/channel is good. Capacitance should be 10,000 - 15,000uF capacitors in each PSU.
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Thanks for your reply.
Yes, my current F5 is quiet. It is mounted on two separate monobloc psu. So I have two smaller chassis that come in my cabinet configuration. I like the F5 and simply want more power.
I would appreciate that could clarify which is recommended for each channel separately how much power and filtering capacity must be used.
If I build a single 5U chassis would have to reposition all my devices ... including the turntable !
. I will estimate costs and decide.
Yes, my current F5 is quiet. It is mounted on two separate monobloc psu. So I have two smaller chassis that come in my cabinet configuration. I like the F5 and simply want more power.
I would appreciate that could clarify which is recommended for each channel separately how much power and filtering capacity must be used.
If I build a single 5U chassis would have to reposition all my devices ... including the turntable !
. I will estimate costs and decide.
300 BottomX 22 width X 12 high. My monoblocks:
http://www.diyaudio.com/forums/pass-labs/188691-illustrated-guide-building-f5-13.html#post2596358
His recommendation is the same configuration as I have for the F5. I could exaggerate the psu with F5?
Sorry if my questions are absurd but I want to be sure of what I'm buying. I prefer oversize components that fall short