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Old 14th June 2013, 03:46 PM   #11
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Borys,
could you post Eagle files?

Regards
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Old 14th June 2013, 06:20 PM   #12
PMI is offline PMI  United States
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These are some excellent test results Borys! Especially the THD measurements.

Can I ask which Hantek you used to do these tests? There are several of them, and I know some have better reviews than others.
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Old 14th June 2013, 07:37 PM   #13
borys is offline borys  Poland
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Quote:
Originally Posted by PMI View Post
These are some excellent test results Borys! Especially the THD measurements.

Can I ask which Hantek you used to do these tests? There are several of them, and I know some have better reviews than others.
I am using portable dso1060 scope as I work a lot on the cars.
I must upgrade my sound card and function generator. The amp is made without matching any of the components - just stright from the bag parts.


There are eagle files anyway.

I can maybe draw the n-channel version but I do not want to upload not tested version.
Attached Files
File Type: zip FET-hex v6.zip (91.3 KB, 487 views)
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Old 14th June 2013, 08:04 PM   #14
Bigun is offline Bigun  Canada
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A nice design and a nice build - well done!
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"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
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Old 14th June 2013, 08:28 PM   #15
borys is offline borys  Poland
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Quote:
Originally Posted by Bigun View Post
A nice design and a nice build - well done!
THX

If Ill have some free time I am going to put 2nd pair of o/p tranies and lift up the supply voltage, but I must do some tests first.
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Old 14th June 2013, 08:47 PM   #16
PMI is offline PMI  United States
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Quote:
Originally Posted by borys View Post
I am using portable dso1060 scope as I work a lot on the cars.
I must upgrade my sound card and function generator. The amp is made without matching any of the components - just stright from the bag parts.
Yeah, there's always something better you can upgrade to (chuckle). I had a National instruments DAQ card and some LabView apps that did an excellent job, but none of that stuff worked with Windows 7 or later (sigh). I would be interested in comparing some notes on that, because I feel a bit handicapped with just my standalone scopes.

The input pairs I am using on my version of Shaan's PeeCeeBee were matched. Feedback resistors also. Nothing else. KSA/KSC pair cannot be matched in D/E versions, and I think there is no point matching the mosfets. I did adjust the gate R values however, according to the gate capacitance of the mosfets, similar to what LC did.

Frankly, I am surprised the harmonic distortion measured as low as it did. Again, good job!
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Old 14th June 2013, 08:48 PM   #17
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Quote:
Originally Posted by borys View Post
There are eagle files anyway.
Thanks a lot, borys.

I can't open files, maybe I have earlier version.
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Old 14th June 2013, 10:00 PM   #18
borys is offline borys  Poland
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Quote:
Originally Posted by dobrivoje View Post
Thanks a lot, borys.

I can't open files, maybe I have earlier version.
My files are from 6.2.0 version.
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Old 14th June 2013, 11:48 PM   #19
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I downloaded 6.4.0 light and now it's OK.

Thanks again, borys.
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Old 18th June 2013, 07:21 AM   #20
borys is offline borys  Poland
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Currently I am working on upgraded more powerfull version of FET-hex amplifier.
The new version has code name BG2-fet.
It will have 2 pair of outputs (or more). One of forum meber advised to add double bootstrap for vas stage, and so far is working great.
There psu voltage is not wasted anymore. At the moment I have only 80W transformer so further test and developments will be required after Ill get bigger buddy.

Bellow results:

THD
Measurement is allways with amplitude 20V just to compare all my amps. Unfortunetly my sound card has some artefacts on measurements, I hope I will have time to upgrade it.


boot21-Clipping
Output voltage on 8R load vs vas bootstrapped voltage

boot23 and 24
Supply voltage vs output voltsge 8R load, as you can see amplifier is very very efficiednt (thanks to raven and mr zbig from my forum).

boot25
Sypply voltage vs 50Hz square - you can see my 80W transformer has drop the load :P

boot26
Clipping vs bootstrap again

boot28
some RNB song

boot27
Here I have small question - from approx 4kHz the bootstrapp is starting to collapse a bit, I do not know If I have to be woory about it cause the power spectrum of music signal for higher F is not as high as for lower F's.

BG2-fet
The test amp itself (temporarly with one pair of outputs and no source resistors - there will be a time for them further)
Attached Images
File Type: png fet-hex bootstrap v2.png (69.6 KB, 1385 views)
File Type: png fet-hex bootstrap v2 5kHz.png (60.1 KB, 1325 views)
File Type: png boot21.png (136.6 KB, 1312 views)
File Type: png boot23.png (127.1 KB, 1256 views)
File Type: png boot24.png (125.4 KB, 1217 views)
File Type: png boot25.png (111.9 KB, 122 views)
File Type: png boot26.png (117.0 KB, 120 views)
File Type: png boot28.png (139.9 KB, 131 views)
File Type: png boot27.png (127.0 KB, 137 views)
File Type: jpg BG2-FET.jpg (93.1 KB, 395 views)

Last edited by borys; 18th June 2013 at 07:32 AM.
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