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F5 pcb group buy...

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#181
speakrsrfun said:
... use multiple caps to achieve a higher capacitance rating on board.
Click to expand...

Oh, c'mon. I used to do crazy stuff like that too, but presently I'm of the notion that a single cap DO sound better. That's why you will not see multiple caps on my PS boards😉

speakrsrfun said:
I’m just worried that I’m going to have a hard time finding Caps with high enough rating cheap enough for me to use as F5 supply caps. Unless you have some laying around your willing to sell….
Click to expand...

I'm sure you will find suitable single can caps realtively cheap in DigiKey catalog. If not, the ones in a picture are for sale.
 

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#182
Point taken Peter, here I am striving for simplicity and I'm thinking of wiring multiple cap banks LOL. I'll take a look around and see what I come up with, I'm sure the PS boards will not be ready for some time yet so it will give me some time.

OK so now I'm off to look for some cheap can caps, Thanks again for the reply Peter it helps me fall off the fence I've been teedering on, Peace and keep well.


Peter Daniel said:


Oh, c'mon. I used to do crazy stuff like that too, but presently I'm of the notion that a single cap DO sound better. That's why you will not see multiple caps on my PS boards😉



I'm sure you will find suitable single can caps realtively cheap in DigiKey catalog. If not, the ones in a picture are for sale.
Click to expand...
 
#186
You know what Peter I was looking at the Jensens on the PartsConnextion site and though I'd love to spend $160/amp on supply caps I'm afraid the $320 for the pair puts this into the ridiculous category for my wife.

I had a few caps picked out from Digikey but wanted to wait for supply boards before I made a jump.

I'll go Panasonics for now and if I don't like I'll go Nichicons or Jensens, but it will have to be a drastic improvement for me to even consider the price increase.

Take care.
 
#193
F1 FAN:

I'll answer that for you, although I'm not Peter here is what he said above....

"I actually run out of F5 amp boards, and since there is still demand for those I will order PS boards as well."

So no F5 boards and no PS boards for a few weeks it seems.

Peace and keep well.
 
#194
speakrsrfun said:
F1 FAN:

I'll answer that for you, although I'm not Peter here is what he said above....

"I actually run out of F5 amp boards, and since there is still demand for those I will order PS boards as well."

So no F5 boards and no PS boards for a few weeks it seems.

Peace and keep well.
Click to expand...
Thanks I read through most of the thread but I missed that post.I shall order when there ready.
 
#196
f5 & ps boards and bridging

Peter
I would also be interested in another set of f5 boards(2 boards) and two more PS sets(4 boards)
I built the f5 last weekend with the revised feedback network and without the current limiting or the thyristor- I like what I hear.

Next step is bridging the channels for mono blocks-
two questions for those who care to "listen"- and hopefully reply

1) simply connect inputs and outputs? Positive to positive and negative to negative? Is that all there is?
2) and to bias(5k trimpots) keep the outputs separate until .59 dc across r11 & r12 with 0 vdc at the outputs and then tie the ouputs together for roughly 50 watts of lovely class A? is that all there is?
inquiring minds wanna know
godd weekend to all
rob
 
#198
f5 bridged

peter
thanks for the reffernce to the f4 manual-
so bridged really is that straight forward-
tie the inputs of the f5 boards together, for either left or right, ie two boards per channel vs the usual arraingement of one board per channel and tie the outputs together-
adjust bias after warm up-
again I assume that bias is set per board and my guess is that it would be imperative to get them both close to the 0vdc @ .59vdc across r11 & r12-
I'm thinking(dreaming) separate torroids with their own 2.5 amp fuses and two power cords-sounds like fun don't it?
anyone have any say on sound quality/trade-offs with bridged operation?

someone reffered to an e-bay seller with nice heatsinks for about $45 US but I couldn't find the reference tonight- anyone else see this?- they looked like a very good fit for the project- as memory serves me 2" fins, 10" x 12" with a vertical orientation- anyone with a better recall find that link?
take care all
rob
 
#199
Re: f5 bridged

rob lenk said:
so bridged really is that straight forward-
tie the inputs of the f5 boards together, for either left or right, ie two boards per channel vs the usual arraingement of one board per channel and tie the outputs together-
adjust bias after warm up-
again I assume that bias is set per board and my guess is that it would be imperative to get them both close to the 0vdc @ .59vdc across r11 & r12-
Click to expand...

Not exactly, what you are describing is parallel connection of two channels. Bridged is completely different matter. You are not connecting inputs and outputs together. Instead you feed the other channel with a signal of opposite polarity and connect speaker between two channel outputs, without reference to ground.

The bias does not need to be readjusted, it's still exactly the same as for a single channel, but insted of using two mono amps (as for regular stereo) you are now using 4 amps (2 per mono channel).
 
#200
F5 Feedback Modification Question

Have plans to modified my F5 feedback network relative to Nelson's suggestion. Quote cut and paste from the previous postings - "( R11 & 12 to 1 ohm/
R5 & R8 to 100 ohms and R1 & R2 to 22ohms-pass site)"

Please let me know if if I have this correct. I assumed the net result for R5 & R7 in parallel , R8 & R6 in parallel, for each pair is 100 ohms. I purchased quanty 4, 200 Mills MRA-5 resistors for positions R5 & R7, R6 & R8.

Have I made a correct assumption ?
 
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