distortion adjustment update
![Before[1].jpg](https://www.diyaudio.com/community/data/attachments/363/363732-bcecfc5c4d6528a4c4b9270ad12823bf.jpg?hash=vOz8XE1lKK "Before[1].jpg")
![After[1].jpg](https://www.diyaudio.com/community/data/attachments/363/363738-9b78eb0ff44ffb03d87a4d828b8357af.jpg?hash=m3jrD_RP-w "After[1].jpg")
After some circuit arrangements, I managed to get these results, I would be happy if some expert GURU wanted to comment on them.
However, tonight the listening tests .... Aleph 30 vs F5 (r1.2 version) with less negative feedback rate and P3 adjustment.
The first photo shows the results of HD prior to the amendment, the second after.
After some circuit arrangements, I managed to get these results, I would be happy if some expert GURU wanted to comment on them.
However, tonight the listening tests .... Aleph 30 vs F5 (r1.2 version) with less negative feedback rate and P3 adjustment.
The first photo shows the results of HD prior to the amendment, the second after.
Attachments
Last edited:
I'm not that one (Guru) , but - considering that THD spectra is pretty much the same in these two cases , only your ears can decide what you prefer
Hi!Alex i have just attached one more picture that show the new circuit diagram.
However, the test of fire tonight!
Thanks for your reply.
Be well
Lately Mr AlexeiZ, temp mod when Cal's off again.
(oldy rerun : Alexei Sayle - Didn't you kill my brother? - YouTube )
(oldy rerun : Alexei Sayle - Didn't you kill my brother? - YouTube )
Tests done ... for my ears and those of my friends, (including my friend Roberto, who is a music teacher).
There are no doubts, F5 triumphs for everything, an almost embarrassing surprise although the aleph 30 remains an excellent amplifier, but it can not keep up in terms of dynamics, focusing, micro and macro detail, soundstage depth.
It 'was like removing a veil from the speakers.
I am very satisfied for time spent to optimize my F5.
Greetings to all.
Last edited:
Has anyone noticed that this thread is approaching 2.5M views? Wow! That really speaks to the F5's stature in the audio world. Listening to some Mingus right now on mine.
https://dl.dropboxusercontent.com/u/370002/IMG_4086.jpg
https://dl.dropboxusercontent.com/u/370002/IMG_4086.jpg
I'm starting to think that diyaudio needs a better search engine, it is getting really hard to find information in this post. Maybe it needs a dedicated F5 search engine 🙂
I have a quick question, that I am sure has been answered but I am unable to find a post with that answer. I have fully populated f5 boards but I want to remove the termistors (th1,th2) can I just disconnect them or do I have to remove the associated current limiting components?
I have a quick question, that I am sure has been answered but I am unable to find a post with that answer. I have fully populated f5 boards but I want to remove the termistors (th1,th2) can I just disconnect them or do I have to remove the associated current limiting components?
The thermistors are in the bias circuit, not the limiter. Leave them alone.
If you feel it absolutely necessary to remove the limiter, and I suggest you don't, Remove Q5, Q6, R17, R18, R19, R20, R21, R22
If you feel it absolutely necessary to remove the limiter, and I suggest you don't, Remove Q5, Q6, R17, R18, R19, R20, R21, R22
No I don't want to remove the limiter. Knowing me I will accidentally short the outputs one day and fry my amp. I just wanted to remove the thermistors because the ones I have aren't going to reach the mosfet properly. I mistakenly said current limiting even though I know it is bias (doh). If the amp won't bias properly without them I will just have to get some replacements. Thanks,
They don't need to touch the transistors, but it helps. You can leave them alone and they will still do their job as the inside the case tempature rises.
Just solder some longer legs on the ones you have if you are worried about it. 🙂
Just solder some longer legs on the ones you have if you are worried about it. 🙂
I'm here in heaven, and I didn't even have to die or repent for 60 years of too much living!
I have been listening to my home-brew FirstWatt/Nelson Pass F5 Class A amp (with diyAudio boards and case) and MarkAudio 10p full range speakers in a Pensil home made BB ply cabinet. I have not veneered the cabinets yet (supplies just arrived) but the sound is spectacular.
My wife, who never pays attention to the stereo was stopped in her tracks. Several 'audiophile' friends were floored. Look for Klipsch horns, Vandersteen, and B&W speakers for sale on Craigslist soon. No one, including myself, can believe what we are hearing.
Out goes the homebrew EL84 amp, my previous reference. Even the Marantz 8B didn't stand a chance against the Pass design.
Amazing what you can get for US$800 and a bit of handiwork. And, thanks to all the people who contributed their time and effort on diyAudio for my 'Stairway to Heaven'.
I have been listening to my home-brew FirstWatt/Nelson Pass F5 Class A amp (with diyAudio boards and case) and MarkAudio 10p full range speakers in a Pensil home made BB ply cabinet. I have not veneered the cabinets yet (supplies just arrived) but the sound is spectacular.
My wife, who never pays attention to the stereo was stopped in her tracks. Several 'audiophile' friends were floored. Look for Klipsch horns, Vandersteen, and B&W speakers for sale on Craigslist soon. No one, including myself, can believe what we are hearing.
Out goes the homebrew EL84 amp, my previous reference. Even the Marantz 8B didn't stand a chance against the Pass design.
Amazing what you can get for US$800 and a bit of handiwork. And, thanks to all the people who contributed their time and effort on diyAudio for my 'Stairway to Heaven'.
CRCook I am on a similar elevated plane of existence, now, as well. Running my F5 from a boozhound phono pre, 5687 Aikido, pushing everything out through Speedster speakers, and it's just great.
I've never heard anything like it, but then again, I'm a relative audio rube coming from Infinity or Polk + NAD gear. Mr. Pass is now a permanent fixture on my hero list.
I am really looking forward to putting the Aleph J into the 4U chassis, this summer. If only to see the smiling cockroach that Zen Mod mentioned... 🙂
At 64F this winter in my basement, the F5 barely breaks a sweat. I'll re-check the bias once things warm up in late Spring.
I've never heard anything like it, but then again, I'm a relative audio rube coming from Infinity or Polk + NAD gear. Mr. Pass is now a permanent fixture on my hero list.
I am really looking forward to putting the Aleph J into the 4U chassis, this summer. If only to see the smiling cockroach that Zen Mod mentioned... 🙂
At 64F this winter in my basement, the F5 barely breaks a sweat. I'll re-check the bias once things warm up in late Spring.