Boss - FA-1 Fet Amplifier [schematic]
- Duckman
- Opamp Operator
Hi, guys!
After my search for options, here's the problem:
reading some reviews about the FA-1, I became interested in build it, so I breadbord it first, but for some reason got less volume than I expected. To make it short, I checked, double and triple checked, change parts, change breadboard and... nothing... still a kind of 1:1 volume. I never got the oportunity to try one of this, but I see reviews that claim it as a louder device. I also read here that some factory schems have "mistakeks" included.
Maybe the problem it's obvious for someone with a little more knowledge than me
If someone used this schem without a problem, I accept any help.
Tkx!
After my search for options, here's the problem:
reading some reviews about the FA-1, I became interested in build it, so I breadbord it first, but for some reason got less volume than I expected. To make it short, I checked, double and triple checked, change parts, change breadboard and... nothing... still a kind of 1:1 volume. I never got the oportunity to try one of this, but I see reviews that claim it as a louder device. I also read here that some factory schems have "mistakeks" included.
Maybe the problem it's obvious for someone with a little more knowledge than me
If someone used this schem without a problem, I accept any help.
Tkx!
- Attachments
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- Boss_FA-1_FET_Amplifier.pdf
- Boss FA1 Fet Amp
- (39.41 KiB) Downloaded 714 times
- Duckman
- Opamp Operator
Ok, got it.
Maybe somebody got the schems or some gut shots of the Analog Man version to see diferences by my self?
Tkx!
Maybe somebody got the schems or some gut shots of the Analog Man version to see diferences by my self?
Tkx!
- Attachments
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- fa-1-clone.jpg (9.65 KiB) Viewed 7283 times
- roseblood11
- Tube Twister
Hi,
I think the schematic is correct. And as far as I know, it IS a very loud unit...
The same schematic is published on ustomp: http://ustomp.com/?p=6,
but he uses a different opamp in his layout.
He claims that C2 is a "non-polar 47F cap", but he must have misread the schematic, I´m sure that it says "0.47µF np"...
Did you use the HA1457W opamp?
regards, Immo
I think the schematic is correct. And as far as I know, it IS a very loud unit...
The same schematic is published on ustomp: http://ustomp.com/?p=6,
but he uses a different opamp in his layout.
He claims that C2 is a "non-polar 47F cap", but he must have misread the schematic, I´m sure that it says "0.47µF np"...
Did you use the HA1457W opamp?
regards, Immo
- Duckman
- Opamp Operator
Thanks for your post, Immo!
I noticed that C2 value is a little unclear, so I tried both values, and I don't ear a big difference. Also, I buyed the two HA1457W and the 2SK246GR at Small Bear, trying to keep the original configuration, but no "loudest" at all.
What about R5? Is the only value not printed, just handwritten. Maybe...?
In order to reach some satisfaction, I'll try the 4558/J201 version, just in case... and I tell you when I'm done.
Thanks for your time!!
I found this too:
I noticed that C2 value is a little unclear, so I tried both values, and I don't ear a big difference. Also, I buyed the two HA1457W and the 2SK246GR at Small Bear, trying to keep the original configuration, but no "loudest" at all.
What about R5? Is the only value not printed, just handwritten. Maybe...?
In order to reach some satisfaction, I'll try the 4558/J201 version, just in case... and I tell you when I'm done.
Thanks for your time!!
I found this too:
- Attachments
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- fa-1pcba.jpg (25.86 KiB) Viewed 7258 times
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- fa-1clone.jpg (32.63 KiB) Viewed 7258 times
so I want to confirm that the original schematic is 100% correct and that cap is a 0,47uF, not a 47uF. I have the original pedal at home and compared with the clone I can't tell any difference.
the pedal shown in the attached pic is not mine, it's another version of the FA1 based around another IC, but the rest is identical (except the ceramic caps, different values and different connection with the IC), and you can see C2 0,47uf. I will add some pics of mine too.
the pedal shown in the attached pic is not mine, it's another version of the FA1 based around another IC, but the rest is identical (except the ceramic caps, different values and different connection with the IC), and you can see C2 0,47uf. I will add some pics of mine too.
Last edited by Dimitree on 11 Mar 2011, 20:55, edited 1 time in total.
this is the other version
it's easy to spot the differences: different IC, 2 more resistors, different values for the 2 ceramic caps. you can notices that those differences are only to adapt this different IC on the circuit
it's easy to spot the differences: different IC, 2 more resistors, different values for the 2 ceramic caps. you can notices that those differences are only to adapt this different IC on the circuit
- Attachments
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- fp2.png (366.01 KiB) Viewed 7223 times
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- fp1.png (355.36 KiB) Viewed 7223 times
Have you got any othe layout¿ In a springboard i think
- iq01221
- Solder Soldier
- Duckman
- Opamp Operator
Well done. In one of the photos posted above by Dimitree, you can see clearly a 0.47uF in the original board, but, as I said before, not a big difference in sound.
Mine, I finally gave it to a friend because I do not settle for the sound.
Mine, I finally gave it to a friend because I do not settle for the sound.
- RnFR
- Old Solderhand
Information
with all these gutshots, ive decided to turn this into the official FA-1 thread, since we don't have one yet.
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Blog-APOCALYPSE AUDIO
- guycapuano
- Breadboard Brother
Anyone have a vero for this one? I had an original here yesterday and am FLOORED!
- guycapuano
- Breadboard Brother
bump anyone?
- guycapuano
- Breadboard Brother
I dont know how yet, I'm a noob remember?roseblood11 wrote:download the "do it yourself layout creator" and make a vero...