A couple questions
1) Is it worth while to build it dual mono (2 300VA 18+18 transformers) as oppesed to using just on 300VA transformer?
2) Does the soft start board have any advantage over the thermistors? Also if usng two transformers I assume there isn't any changes in the way you would hook it up to the terminal block with the thermistors?
3) Would the speaker protection board be a good addition to this amp?
Sorry if some of these question have been asked before, I searched and am stll not totally clear on these points
Thanks
Debra
1) Is it worth while to build it dual mono (2 300VA 18+18 transformers) as oppesed to using just on 300VA transformer?
2) Does the soft start board have any advantage over the thermistors? Also if usng two transformers I assume there isn't any changes in the way you would hook it up to the terminal block with the thermistors?
3) Would the speaker protection board be a good addition to this amp?
Sorry if some of these question have been asked before, I searched and am stll not totally clear on these points
Thanks
Debra
1) not really sure but I built mine dual mono with 2 200va transformers. It sounds geat.
2) I did not use soft start other than the thermistors and I have never had an issue, even turning it off and then on, while hot.
3) Speaker protection boards are always a good idea. I have them.
Hope this helps
1) If you have a 2nd PSU pcb as well, then yes, there is some advantage. However, by that point you might as well make 2 F4 and run them as monoblock. In general just build it stock.
The PSU is the most expensive part after the chassis, so you might as well save it for your next project, as nobody builds just one of these...
2) The Thermistors are really quite effective at keeping the inrush low, and they act as line filters as well. A nice two for one. The SS boards is really cool. If you want to use it, install it only after you have the amp built as stock , working, and happy. Only then add the SS board.
3) It's a neat widget that adds an awful lot of complexity. Like the SS board, add it to your build only after everyting else is working properly
The PSU is the most expensive part after the chassis, so you might as well save it for your next project, as nobody builds just one of these...
2) The Thermistors are really quite effective at keeping the inrush low, and they act as line filters as well. A nice two for one. The SS boards is really cool. If you want to use it, install it only after you have the amp built as stock , working, and happy. Only then add the SS board.
3) It's a neat widget that adds an awful lot of complexity. Like the SS board, add it to your build only after everyting else is working properly
and the quality of the pics allows confirmation that the thread pitch is 0.5mmYes - the longer (Mosfet) screws are M3x10mm, the shorter (PCB into standoff) screws are M3x5mm
That then gives the hole diameter that the thread tap needs to give a full engagement thread. Hole = Thread diameter - Thread pitch = 2.5mm diam.
Thanks for you advice. I only have one chassis, but enough power supply boards and parts to build two seperate power supplies, so I guess I will go the dual mono route for now. I can always convert it to two monoblocks later.
Yes, building these are addictive! This is my first solid state project, though I have built many tube amps. It seems strange building a power suppy that doesn't put out a couple hundred volts or more
Like you said nobody can built just one, I have more tube amps than I know what to do with, and will probably end up with more solid state amp than I need also.
Thanks again
Debra
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Thinking I might as well put the second PSU board together and assemble a dual mono PSU. Will have to order a couple more boards from Peter Daniel for the BA3-FE. The first PSU board is assembled exactly as shown in the F5 thread. Hopefully this is correct. Should the second PSU board be assembled the exact same way? If so, once done, I'll have no idea how to wire the whole thing together. Am I missing anything else?
What hookup wire is evryone using?
For RCA to amp board I am planning on using a 22Ga twisted pair. I have a few colors of 22Ga telfon Alpha wire. Would I be better off using TSP?
For power connections is 16 Ga adequate or should I use 14Ga. Are people using stranded or solid wire here.
Thanks
Debra
For RCA to amp board I am planning on using a 22Ga twisted pair. I have a few colors of 22Ga telfon Alpha wire. Would I be better off using TSP?
For power connections is 16 Ga adequate or should I use 14Ga. Are people using stranded or solid wire here.
Thanks
Debra
I use a mixture of insulated solid core 0.6mm diam and cores from cat5 (~24awg)
The cat5 are much harder, probably hard drawn and so must be prevented from vibrating, else fatigue may set in.
The big advantage of solid core is they stay in place once curved to their final location. Don't "corner" bend twisted pairs. Bend to a gentle radius.
The cat5 are much harder, probably hard drawn and so must be prevented from vibrating, else fatigue may set in.
The big advantage of solid core is they stay in place once curved to their final location. Don't "corner" bend twisted pairs. Bend to a gentle radius.
Whatever you have on hand, and/or in the color you like.
For PSU and GND, use the thickest you can fit. For the signal input, small is better.
Solid or stranded makes little difference, Andrew is right though, solid makes nice bends that stay, and his suggestion of bending to a radius is spot-on.
Are you using one transformer? I would suggest using one PSU board for the time being, getting everything running properly and happy, then adding a second board.
Finished my first F4, parallel monoblock configuration (single ended input).
Only listened to it so far with a tube preamp and old a Klipsch Heresy speaker I have in my lab, but what a great sounding amp,
dead quiet and very detatiled. Next to build the other channel and then try them out in my system driving them with my 45 amp.
Debra
Only listened to it so far with a tube preamp and old a Klipsch Heresy speaker I have in my lab, but what a great sounding amp,
dead quiet and very detatiled. Next to build the other channel and then try them out in my system driving them with my 45 amp.
Debra
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