F5 Listening Impressions & Discussion

crackling sound during warm-up

Hi all,

Posted this also in "F5Turbo Illustrated Build Guide" but had no answer yet.
before screwing things I want to be sure what to do in this matter.

I've some issues with my F5 turbo V2. All is playing very well, however I've strange crackling sound during warm-up on the left-side channel.

It is only the left channel, Power supply feeds both channels, so I can conclude this is not the issue. Right channel is playing silent and after warm-up also the left channel is silent.

Is there anyone who can tell where to start looking te remove this crackling sound. I thought of going over all solder-joints, however is this the right approach?

Nils
 
I did a test which I thought I did allready... decouple the pre-amp and turn on the power-amp. after 1,5 H no crackling sound... The F5-turbo was warm as it was normally

next day re-attach the pre-amp and again no Crackling sound!:eek::confused::confused::confused::eek:

Hopefully it solved itself bij disconnecting and reconnecting the interconnects. If the issue returns I will check the solder joints en the thermal pads. and off course the visual check.

Thanks for the replies
 
I absolutely recommend the F5 for rock and metal! It does monster cymbal crashes with eternal decays. It never seems to run out of umph when I throw Zeppelin or Tool at it.

As for P3, that thing is a game changer. I don't have any real test gear like I wish I had so playing with that thing has been an odessey. I started out with P3 turned more towards the n-channel before I started digging deeper into what it could do. Then I started playing with it a bit more and listening. Earlier this week I dialed the bias way down and set each P3 for exactly 7 turns from click towards the P-channel. I think that's the best sound I've got out of the thing so far. Very lush, warm and fluid. Depth and width seem endless and enveloping while micro details feel more fleshed out and specific. I love playing with this amp like this. I can't measure what I'm hearing, but I know what effects I should be getting and learning to hear them has been an awesome learning experience. I feel like having to depend on my ears instead of test gear has made me a better listener, and if you're building amps that's a pretty good skill to develop. This is a good amp to train that skill on.
 
Dear all,

I'm not sure if this thread is still alive but as my concern is more about the sound impression than building the beast, I take my chance here.

First of all, many thanks to @6L6 for the building guide, thanks to @Zen Mod for the detailed bias instructions and of course big thanks to @Nelson Pass for the design and share.

So, I've just finished the build of this famous F5 (v3 version of the board sold at diyaudiostore) and he is driving my speakers (focal 948) for the past three days.
I don't want to hurt anyone, this is really a question about my feeling in these firsts listening sessions, so please take this as it is, I just want an advice and why not some kind of explanation:
my current/previous amp is a 100W class AB NX-amp designed by @Bonsai from hifisonix which I really like a lot. When switching to the F5, I find it what I would call more "musical", there are more bass, maybe more details than with the NX-amp but the sound seems globally less "enveloping" and is definitely less "analytical". The room is quite big, around 55m2 and the power of each amp is definitely incomparable I guess, 100W vs 25W.
As I still am able to become absolutely deaf with the preamp gain at half with the F5 as the power stage, I feel like it's not a power problem at all but do you think that this feeling of being less enveloped (by this I mean that with the NX-amp the sound seems to come smoothly from all around and that with the F5 I feel it is coming straight from the speakers in front of me) is due to power and that opting for a F5T of 50W would change the game or is this in the nature of this amplifier?
Whatever the answer is/could be, my mantra is to have fun before anything and I definitely have with both these amps, I'm just asking for your opinion concerning this feeling (nothing scientific from me here).
Best to all and one more time: THANK YOU!
 
Official Court Jester
Joined 2003
Paid Member
- be informed what THD Spectra is of amp you prefer
-be informed what (actual) THD Spectra is of amp you less prefer
  • be sure that SPL is same for comparing purposes ...... or - heck with that - just enjoy in amp for some longer time and then just be clear how much you enjoyed
  • be sure that you're not clipping amp (that one of lower power)

after that , draw conclusions; good thing is that F5 ( with twiddledee trimpot in input JFet sources) can be set in various ways.... even if that process is sorta tedious if you're not exactly used of doing it on at least weekly basis
 
Member
Joined 2005
Paid Member
Dear all,

I'm not sure if this thread is still alive but as my concern is more about the sound impression than building the beast, I take my chance here.

First of all, many thanks to @6L6 for the building guide, thanks to @Zen Mod for the detailed bias instructions and of course big thanks to @Nelson Pass for the design and share.

So, I've just finished the build of this famous F5 (v3 version of the board sold at diyaudiostore) and he is driving my speakers (focal 948) for the past three days.
I don't want to hurt anyone, this is really a question about my feeling in these firsts listening sessions, so please take this as it is, I just want an advice and why not some kind of explanation:
my current/previous amp is a 100W class AB NX-amp designed by @Bonsai from hifisonix which I really like a lot. When switching to the F5, I find it what I would call more "musical", there are more bass, maybe more details than with the NX-amp but the sound seems globally less "enveloping" and is definitely less "analytical". The room is quite big, around 55m2 and the power of each amp is definitely incomparable I guess, 100W vs 25W.
As I still am able to become absolutely deaf with the preamp gain at half with the F5 as the power stage, I feel like it's not a power problem at all but do you think that this feeling of being less enveloped (by this I mean that with the NX-amp the sound seems to come smoothly from all around and that with the F5 I feel it is coming straight from the speakers in front of me) is due to power and that opting for a F5T of 50W would change the game or is this in the nature of this amplifier?
Whatever the answer is/could be, my mantra is to have fun before anything and I definitely have with both these amps, I'm just asking for your opinion concerning this feeling (nothing scientific from me here).
Best to all and one more time: THANK YOU!
Hi B. This is not scientific either, and others here are far more knowledgeable than I, but when I built my Aleph 5 it took three weeks of use before it sounded reasonable, and a further three to give nearly of it's best. This was with it playing for six hours a day. (I played request music from my neighbours...).
 
- be informed what THD Spectra is of amp you prefer
-be informed what (actual) THD Spectra is of amp you less prefer

Sure, I'll try to measure that.

  • be sure that SPL is same for comparing purposes ...... or - heck with that - just enjoy in amp for some longer time and then just be clear how much you enjoyed
  • be sure that you're not clipping amp (that one of lower power)

I'll check that too but from my perspective the F5 is loud and clear, it only "suffers" from being more "directional". As I said it's mainly feeling.
And I'll also listen to it more, good things are getting better when getting older

after that , draw conclusions; good thing is that F5 ( with twiddledee trimpot in input JFet sources) can be set in various ways.... even if that process is sorta tedious if you're not exactly used of doing it on at least weekly basis
Oh oh, I'm definitely not used to do that :) However if you have any pointer on documentation concerning this I'd definitely enjoy learning. I'll check for that on the different threads. Thx!
 
Hi B. This is not scientific either, and others here are far more knowledgeable than I, but when I built my Aleph 5 it took three weeks of use before it sounded reasonable, and a further three to give nearly of it's best. This was with it playing for six hours a day. (I played request music from my neighbours...).
Hi J ;)
Thanks for this non scientific advice :) This is definitely useful: I guess that I'm too much looking to compare to the other one and need to take more time to taste this new one and that it may simply get better with the time. Thx!
 

ra7

Member
Joined 2009
Paid Member
Here’s more unscientific advice: try flipping the polarity on the speakers. Also listen for longer. I’ve observed that going from one harmonic profile to another takes a while to get used to. Your brain seems to want to unlearn the old one and learn the new one.
 
Well,
I also found my F5 unusual at first. It also had problems being directly controlled by my tube phono. Of course the phono stage had the problem... with a buffer stage the whole thing suddenly sounded fantastic! The sound of your old amplifier is not only dependent on the speakers. It also depends on the control! A preamp with muscles can sometimes help.

Best regards
Arndt
 
Hey all,
just adding a short feedback a week after my initial post concerning the F5 vs NX-Amp listening impression: the F5 is absolutely great.
I thought I would never write what I'm going to write but it seems that my main issue may have been mainly wiring related. After many different tests scenarios like for example changing the preamp or calling Mulder and Scully from the X-Files, I finally changed my RCA cables between the pre and the amp and it gaves immediately a lot more openness (ear me, I did not invest in cables at hundreds of billions of dollars, I simply bought quite good and well shielded RCA cables [around 50€ of invest, nothing incredible]).
As mentioned earlier It does not sound as "enveloping" and present as the NX-amp but it definitely is doing better (to me) than the previous one when it comes to precision in the details, musicality and things like that. To sum-up: a lot of pleasure here.
Thanks for all the suggestions, both the scientific and non scientific ones, it really helped.