F5 Listening Impressions & Discussion

[Tea-Bag]

Originally Posted by buzzforb

Are you talking about the Toshibas in Juma's version. I listen to FR drivers like you, so your advice is helpful.

I have those Fets too - it's on the bucket list of boards to build. I was thinking of using just two or even one-
These are the big TO-262 (I think) Toshibas.
At first I loved it though, better nuance in detail.
I've heard good things on the little one's for sure.

Too bad alot of this stuff is obsolete. I've been hoarding what I can.
I must try some TO-220 FQPs as well, since they are available online for reasonable costs. Reasonable inexpensive is a principle I like to adhere to, even if in practice I dont always achieve it. I moved to solid state after transformers and copper prices shot out the roof.

[buzzforb]

I can only say that you need to try the Juma version.Very simple and there is evena layout for etching your own boards. I have some fets i can sell you for $5 per pair matched to .1V. I coming off Aleph J monoblocks and like this better. At first i thought it was cold, but after listening in my main system, it is wonderful top to bottom. Has much better control over low end.

[a.wayne]

Has anyone compared the full Cvilier setup yet ..?

[alazira]

Originally Posted by Tea-Bag

The F5 is hard to beat. I've built a lot of these variations. I think the F2J atmospheric presentation and highs are even better, but it can't always deliver complex stuff. I think I've said before, I find the R1 variation with FQA's a bit more laid sweet sounding, with a little less dullness than the toshiba's-which I enjoyed for quite some time.

Hi Tea-Bag,
The "R1" variation you mention, that's the one with .68ohm R7/R8, 4.7K R1? Did you use 2SJ108/2SK370?
F5 power amplifier

[vdi_nenna]

F5 R1? How did I miss this?

[Bksabath]

Originally Posted by Tea-Bag

I have those Fets too - it's on the bucket list of boards to build. I was thinking of using just two or even one-
These are the big TO-262 (I think) Toshibas.
At first I loved it though, better nuance in detail.
I've heard good things on the little one's for sure.

Too bad alot of this stuff is obsolete. I've been hoarding what I can.
I must try some TO-220 FQPs as well, since they are available online for reasonable costs. Reasonable inexpensive is a principle I like to adhere to, even if in practice I dont always achieve it. I moved to solid state after transformers and copper prices shot out the roof.

Hi Tea bag I have 100 (well almost as I am using same)
FQP19N20
I am using them with the FQA12P20 complements witout problems

If you need same let me know
I am matching them at 24 V 2A constant 50 C

[Tea-Bag]

Originally Posted by alazira

Hi Tea-Bag,
The "R1" variation you mention, that's the one with .68ohm R7/R8, 4.7K R1? Did you use 2SJ108/2SK370?
F5 power amplifier

Yes, that one.
Just 2SK170, 2SJ74's. (I got from a member here)
I used no P3, std 10R for now. I have no distortion analyzer. I am interested in getting a USB solution if I can find one.

Originally Posted by Bksabath

Hi Tea bag I have 100 (well almost as I am using same)
FQP19N20
I am using them with the FQA12P20 complements witout problems

If you need same let me know
I am matching them at 24 V 2A constant 50 C

I am all set for now, I have 25 pairs of the FQA N's and P's
Although the little critter one's should keep the amp build able with fairchilds into the future.
I figured since Papa was using them in R1, then I should go that route, not standard IRF's or Toshiba's

[alazira]

Originally Posted by Tea-Bag

I used no P3, std 10R for now. I have no distortion analyzer. I am interested in getting a USB solution if I can find one.

I'd like to find a USB distortion analyzer as well. Tuning P3 by ear and getting both channels to perfectly match would be difficult.

[generg]

My USB solution

E-MU 0204 and software for windows or Mac OS x, there are even free offers..

I was inspired by this discussion....

Virtins - Multi-Instruments Software

[DJNUBZ]

So I just switched my F5 from CRC to CLC using a 2mH inductor. The supply rails dropped a little and I biased the amp at .5V. Here are my initial findings, I have not had much time listening to it.

Bass is MUCH better, I didn't realize it was missing until I made the change. Everything sounds like it has much more weight behind it.

Dynamics seem to be a bit less, personally I love dynamics so I am not sure if I like this change. I am not sure if this is due to the lower rail voltage or something else going on. Would bypass caps possibly improve this? What about an increase in bias, the amp runs pretty cool.

The sound is a smoother, this could be due to the change in dynamics though.

I only have a few min on the amp but I will update this once I have some more listening time on the amp.


Next planed mod - P3.