F5 Listening Impressions & Discussion

[tinitus]

F5 is created to drive "easy" speakers

BA-1 and BA-2 have been designed especially fore our quest to drive more "problematic" speakers

We need to mate F5 with properly matched speakers, to do a fair "listening evaluation"
F5 is not supposed to drive any crazy speaker out there
It will probably only really shine with properly matched peakers

Using this or that kind of resistor comes second, in my opinion
When some people prefer a certain component, it could easily relate to a great number of other things
Things that may very well be completely different in other situations
You need to figure a much bigger perspective

It could seem like many "newbies" waste way too much energy on trying to do "the impossible"
Some may even fail because of that

[Tea-Bag]

Originally Posted by vdi_nenna

Tea-bag

When you say, "I dont think Caddocks are forgiving resistors." What do you mean exactly?
I interpret this as they may be clinical or critical of the sound. Like not soft or warm?
I want critical.

Yes, I have thought about the Toshibas. I held some in my hands yesterday. Not mine though.

Why not? Gone this far, right?

I have even thought about the "naked" Vishay resistors.

Lord forgive me. For I know not what I do. Well...maybe I do!

I usually dont mean too much. I think caddocks are a very good resistor - they are honest and quite detailed. Does that make them perfect for audio...I dont really know. I prefer PRP's now in most places.
PRP's and Dale RN/CMF are pretty close IMO. Carbon Films I think color the music too much for me. So I am probably closer to your kind of ears.

I actually am trying Caddocks in F5 in R11,12 R5-6 positions, these are the MP9xx resistors. Hopefully will have something to report soon. This will be the 4th F5 clone I've built (using the same sinks). I really like this amp.

[vdi_nenna]

I really like this amp.

.

I agree. People who own large Krell amps heard my first attempt and were impressed.
Also guy who own Spectral and $9k tube amps liked it very much.
Dollar for dollar, it means something. It means it is a very good design. I'm proud to own it.

[bear]

Teabag, by 'easy speakers' do you mean above 4 ohms or do you mean not reactive loads??

_-_-bear

[labjr]

Originally Posted by vdi_nenna

.

I agree. People who own large Krell amps heard my first attempt and were impressed.
Also guy who own Spectral and $9k tube amps liked it very much.
Dollar for dollar, it means something. It means it is a very good design. I'm proud to own it.

I notice you have CAT5 speaker cables. Which recipe did you use? How do they sound?

Thanks

[tinitus]

Originally Posted by bear

Teabag, by 'easy speakers' do you mean above 4 ohms or do you mean not reactive loads??

_-_-bear

I think it was me saying "easy speakers"

I knew it wasnt very clear
Mostly it relates to exactly what you mention
I know that
And that the F5 should handle well

With "easy" I meant, not too low sensitivity, but maybe also best to avoid heavy coned drivers, but not sure about that one
But 4ohm speakers combined with a lowish 88db sensitivity would seem like the worst option
Maybe worth to notice that most speakers are usually no higher than 6ohm in the demanding lows
And if its only 85db it might hurt

An "easy speaker" could be 2-3ohm, if it would be 99db
Or a 4ohm, if being maybe 95db
Just rough guessing

[a.wayne]

Originally Posted by Peter Daniel

Yes, 300VA Plitron with 50,000uF total capacitance in stereo or per monoblock.

Hello Peter ,
Maybe the difference is the load . I can believe the dual Tranny supply having a bigger difference at 4 /2 ohm operation vs 8 ohm ...

regards,

[tinitus]

With this size amp, I think its mostly a matter of whats most convenient fore the box design you have planned
At least as long as we stick to original design with one output pair, bias etc
If more output devices, higher bias etc, ofcourse things changes

But sure, if you drive it very hard into classAB, things may change in favour of more trafo power
It might be able to handle close to 100watt classAB into 2ohm, maybe 70-80watt with less distortion
I have no idea how it will sound tho, a wild guess

But basicly I try to aim at a 1 : 10 ratio, pr channel, regarding amp to trafo
Becomes exeedingly difficult with higher power amps, but no problems with smaller ones
Dont know if it makes sense to aim at a 1:20 ratio, but thats possible too, easily

[Peter Daniel]

Originally Posted by a.wayne

Hello Peter ,
Maybe the difference is the load . I can believe the dual Tranny supply having a bigger difference at 4 /2 ohm operation vs 8 ohm ...

Could be, my speakers are 8ohm/100dB

[a.wayne]

Originally Posted by tinitus

With this size amp, I think its mostly a matter of whats most convenient fore the box design you have planned
At least as long as we stick to original design with one output pair, bias etc
If more output devices, higher bias etc, ofcourse things changes

But sure, if you drive it very hard into classAB, things may change in favour of more trafo power
It might be able to handle close to 100watt classAB into 2ohm, maybe 70-80watt with less distortion
I have no idea how it will sound tho, a wild guess

But basicly I try to aim at a 1 : 10 ratio, pr channel, regarding amp to trafo
Becomes exeedingly difficult with higher power amps, but no problems with smaller ones
Dont know if it makes sense to aim at a 1:20 ratio, but thats possible too, easily

I will let you know in a few weeks , doing F5 with double outputs, higher bias , big supply .....