Soft start goes before the transformers. If you are planning on the DIYaudio one, there is a mains neutral, hot/switch out, and switch in. Then after all the circuitry controled mains out to the transformer.
The speaker DC board goes from the speaker out of the amplifier board into the DC board, then out to the speaker terminals.
Read the soft start thread as there is a capacitor value that can be changed depending on how long you want the soft start to wait before switching the relay.
If you do not have the transformer already, most here use the 18vas with 2 secondaries instead of center tapping. you will have 18vac coming out of the transfomer which after it is converted to DC will turn into around 24 volts
In the interest of setting realistic expectations, 18 Vac secondaries will yield 22.5V DC rails or a little higher. This depends on the rectifiers and bias current. Better rectifiers will drop less voltage. Spend some time looking for alternatives to the usual GBPC35xx, such as the VS-MB series from Vishay.
Consider building a dual mono supply with a pair of 300VA transformers.
Consider building a dual mono supply with a pair of 300VA transformers.
Oh yes definitely. And if you want to future proof a little, get a 5U case. That was one thing I wish I would have done as the cost difference is it that much in regards to the whole project cost.
Anything else we should add?
Anything else we should add?
Well, there are some alternate bias circuit options for the F6. My favorite is using three small green LEDs in place of the zener diode. A search in this thread should turn up the modification.
The F6 can benefit from higher bias, and the LEDs have a negative temperature coefficient that lets the amp settle into its thermal equilibrium a little faster at a higher bias levels.
The F6 can benefit from higher bias, and the LEDs have a negative temperature coefficient that lets the amp settle into its thermal equilibrium a little faster at a higher bias levels.
And more question for your insight and experience.:
Rectifier question:
Would this be acceptable or overkill?
VISHAY Single Phase Bridge Rectifier, 25 A / 35 A
https://www.digikey.com/en/htmldatasheets/production/1398081/0/0/1/vs-mb-series.html
Build value added F6 and ACA quality questions:
(1) any known issues with using an audio quality EMF filter sealed can?
(2) any known issues with a DC speaker protection ckt.?
(3) double torrid build on F6... for the money increase, would you build it this way?
AND... should I delete my previous post images to save server space?
I genuinely appreciate your help.
Rectifier question:
Would this be acceptable or overkill?
VISHAY Single Phase Bridge Rectifier, 25 A / 35 A
https://www.digikey.com/en/htmldatasheets/production/1398081/0/0/1/vs-mb-series.html
Build value added F6 and ACA quality questions:
(1) any known issues with using an audio quality EMF filter sealed can?
(2) any known issues with a DC speaker protection ckt.?
(3) double torrid build on F6... for the money increase, would you build it this way?
AND... should I delete my previous post images to save server space?
I genuinely appreciate your help.
Attachments
If anyone is interested I have a set of diyaudiostore purchased F6 PCBs for sale
https://www.diyaudio.com/community/threads/f6-pcb-boards-new-from-diyaudiostore.397138/#post-7303839
I built a stereo F6 a few years ago and bought extra boards thinking I would eventually go to monoblocks F6s, but I love the standard stereo F6 too much! My lose is your gain
Mods please let me know if this is not allowed 🤔
https://www.diyaudio.com/community/threads/f6-pcb-boards-new-from-diyaudiostore.397138/#post-7303839
I built a stereo F6 a few years ago and bought extra boards thinking I would eventually go to monoblocks F6s, but I love the standard stereo F6 too much! My lose is your gain
Mods please let me know if this is not allowed 🤔
No need for EMF filter
I have ran my F6's for years now and no DC never escape to the speakers , even with the water cooled one
double mono is the way to go , for not that much money after all , remenber when you diy you got way more for less than commercial stuff cost 😎
.
The new set of mosfets from the store comes with the irfp049 mosfets and the 9.1v zeners. The last two I ordered for my aleph j build, came with the 240s and 5.5v zeners (I think I measured them correctly. didn‘t need them for the aleph j).
Do the new mosfets have to be used with the 9.1v zeners, as shown in the original build guide, or can the lower voltage zeners still be used with the lower rated R7 and R8? Do the mosfets have anything to do with the zener value?
Do the new mosfets have to be used with the 9.1v zeners, as shown in the original build guide, or can the lower voltage zeners still be used with the lower rated R7 and R8? Do the mosfets have anything to do with the zener value?
This amp was designed for Nchannel Mosfets (and originally the N channel Semisouth power JFETs).
Can you post a clear picture of these Mosfets you received please?
Best,
Anand.
Can you post a clear picture of these Mosfets you received please?
Best,
Anand.
