Particle Accelerator - Alembic F-2B clone

Here are some audios for you to check this hiss thing.

Clips were recorded using a Strat into the pedal, into a line input, a Hi-Z input and a mic input. First bit of playing is always bypassed.
Settings are the same on all clips except on one HiZ where I had to adjust the input gain.


Thanks in advance!! :)


Bump....
 
Hello Sono,

I did listen your sound sample but didn't hear any hiss. Keep in mind that most of the time you only can hear hiss when you don't play. Any guitar sound will be stronger than the hiss.

To make measurement of hiss or buzz il will use a spectre analyser (spectroid for android) i will put my phone to touch the grill clothe of my cab and do a measurement without any sound from the guitar.

You can give it a try.
 
Hello Sono,

I did listen your sound sample but didn't hear any hiss. Keep in mind that most of the time you only can hear hiss when you don't play. Any guitar sound will be stronger than the hiss.

To make measurement of hiss or buzz il will use a spectre analyser (spectroid for android) i will put my phone to touch the grill clothe of my cab and do a measurement without any sound from the guitar.

You can give it a try.

I can hear the hiss perfectly well. Try with headphones. The first bit is the guitar with the FX bypassed, then you will hear a click when the fx is engaged and I can hear clearly a difference. The guitar is not playing at that moment. Maybe I'm exaggerating and the hiss os very faint?
Please listen with headphones to the part when the guitar stops playing and the fx is engaged.

Thanks :)
 
I can hear the hiss perfectly well. Try with headphones. The first bit is the guitar with the FX bypassed, then you will hear a click when the fx is engaged and I can hear clearly a difference. The guitar is not playing at that moment. Maybe I'm exaggerating and the hiss os very faint?
Please listen with headphones to the part when the guitar stops playing and the fx is engaged.

Thanks :)
I did listen with headphones (actually just did it again) no hiss on your sample.

You may hear it while standing in front of the cab, but it is not significant enough to be a problem. It may be improve if you wish by taking a closer look at your Particle Accelerator. For example you may not have the quietest valve.

The particle Accelerator is a low gain effect so low hiss. The input resistor is set like the low input of a amp and the level is decreased before the output.
 
I did listen with headphones (actually just did it again) no hiss on your sample.
Ok. Please listen to this sample and tell me you don't hear a difference between the first half (before the click) and the second one. If you don't hear a difference I'll just shut up Before the clic the pedal is on bypass...

View attachment Hiss.wav

You may hear it while standing in front of the cab, but it is not significant enough to be a problem. It may be improve if you wish by taking a closer look at your Particle Accelerator. For example you may not have the quietest valve.

I have tried different valves and different brands (JJ, Electroharmonix, Telefunken, ECC83, EEC82). No difference.

The particle Accelerator is a low gain effect so low hiss. The input resistor is set like the low input of a amp and the level is decreased before the output.

Well what I want to determine is if that hiss I hear on the recording is "normal" or not. On other pedals I don't hear that difference. Maybe it's inherent to valves? I'm just trying to establish that.

Thanks
 
Ok. Please listen to this sample and tell me you don't hear a difference between the first half (before the click) and the second one. If you don't hear a difference I'll just shut up Before the clic the pedal is on bypass...

View attachment 76406



I have tried different valves and different brands (JJ, Electroharmonix, Telefunken, ECC83, EEC82). No difference.



Well what I want to determine is if that hiss I hear on the recording is "normal" or not. On other pedals I don't hear that difference. Maybe it's inherent to valves? I'm just trying to establish that.

Thanks
No offence but I will not listen your second sample.
It is a technical matter so you need to put number on it. If you don't want to consider my advice to use a spectral analyzer do at least a dB measurement in your daw.
When guitar level is set to -10dB what is your noise floor with and without the Particle Accelerator?
 
Yeah I'm not really hearing any hiss there my dude. If you're happy with the way it sounds then I think it's safe to say your build is working fine.

Ok. I will accept Nathan's answer, although to be honest, I can still hear a difference between bypassed or engaged FX, especially on this audio I posted although Mr. Creach didn't want to listen to it, ignoring what I was saying.:

With all due respect, I understand some things need numbers, and I agree with that point of view, but if I can hear a difference with my ears between BYPASS and FX ON when the guitar is NOT sounding, and there isn't a huge difference in the guitar signal between both states, personally I think I can trust my senses and I don't need a scope to figure out something is not ok. Hence, my original question: is this supposed to be like that? Is it inherent to the design or is there something I might have done wrong? It's not a huge hiss but it's DEFINITELY NOT DEAD SILENT, at least to my ears. So I will accept that the fx is like that and just move on.
In any case, thanks to all for your time and help.
Sono
 
Ok. I will accept Nathan's answer
Yeah I really wish I had a better answer for you, but to be fair my ears also aren't very sensitive so there may be something you hear that I don't. If you really want to go after every hint of hiss you can do things like tubes specially tested for low noise (Tube Depot offers this as a service, though international shipping cost may be a factor), extra low ESR capacitors, audio-spec resistors, etc. It comes down to the balance of how much noise you're okay with vs how much money you're okay spending. For typical live use or recorded use in a mix I've found that I can personally get away with a fair amount of noise before it gets noticeably bad.
 
Don't get me wrong Nathan, TBH the whole point of my question was "am I being paranoid?". I built this thing and the sound is really great. Through my amp the hiss doesn't bother me, it's kinda "natural" if you will, I mean it doesn't hiss more than the speakers if you know what I mean, and the sound is just awesome (both in front of the amp and in the FX return input).

But when I connected it to my mixer's line input, at first I thought I'd need a transformer or some balanced output, thinking that the guitar would sound thin as you would expect from a bare DI, but oh surprise! the sound was just so unmistakably Fender, and the guitar responded so well to dynamics (just like an amp) that with just a tad of reverb, I was litterally overwhelmed and swimming in pleasure :)

Then, when I stopped playing, I noticed the hiss when hitting the footswitch...but I was using headphones so I just wanted to have an external perspective and make sure there was nothing wrong.

I really am very happy with this little wonder! :)
Thanks mate! :)
 
Hi again guys,
I would like to ask for some advice on this please: I want to build an SMD version of the PA. The idea is to get JLCPCB to produce the board and assemble the SMD components on it so I can add the TH ones later. I'm going mainly for 0805 resistors but I can't seem to find 1/4w ones on JLCPCB's site....most resistors that show up are either 125mW or 500mW.
My question is: should I go with 500mW, is 125mW ok for this circuit or I'm not searching properly?

Thanks
Cheers
Sono
 
Hi again guys,
I would like to ask for some advice on this please: I want to build an SMD version of the PA. The idea is to get JLCPCB to produce the board and assemble the SMD components on it so I can add the TH ones later. I'm going mainly for 0805 resistors but I can't seem to find 1/4w ones on JLCPCB's site....most resistors that show up are either 125mW or 500mW.
My question is: should I go with 500mW, is 125mW ok for this circuit or I'm not searching properly?

Thanks
Cheers
Sono
125mW is okay for this circuit. I would definitely be interested to see what you come up with.
 
I will definitely share what I come up with, Nathan. It's the least I can do :)

Thanks
Sono

This is the schematic with some mods to the original PA: Switch to make it compatible with russian 6NxP tubes and be able to place heaters in series/parallel, Switch to use 12ax7 at 9-12v, 2 options for diode clipping (diodes not specified on schem) and the most important part that needs more space on the board, a balanced output to be able to plug the preamp directly into a mixer/soundcard, or to use both outputs at the same time. I'll post the layout as soon as I have it finished.
I'd love to hear your impressions!

Thanks :)
Cheers
Sono
PA variation 02.jpg
 
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