Another GainKlone is alive and singing!

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overmind

overmind

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Joined 2002
geocities.com/overmindxx/
An externally hosted image should be here but it was not working when we last tested it.


My pair GainKlone mono block is alive and singing! Initial testing is very good, no hissing and huming. Good bass, a bit up front and not very at ease, will need some tunning.

I used the non-inverting configuration, with a 4.7uF ERO MKP input cap, input resistance of 50kOhm. I make the gain of the amplifier to be 13 (1 + 621k/49.9k). Temporary power supply is a +/- 22Vac transformer, IRF 40CDP100 Schottky Diodes as rectifier. Nichicon KZ 1000uF 50V along with Wima MKP10 0.22uF 160V by pass cap, another ERO MKP1839 1uF 160V bypassing the +Vcc and -Vcc.

Added two Nichicon KG 15000uF/63V to the power supply, do not like the effect, even more unrelax. Took them off. What else can I do to make it sound more relax?

Oh yes, "heat sinks" are also DIYed. I posted more pictures in my website, check it out.
http://www.geocities.com/overmindxx/


Regards,
SW Yeo

An externally hosted image should be here but it was not working when we last tested it.
 
C

carlosfm

Banned
Joined 2003
it may be dense around here...

...but have you posted a picture?
I can't see anything, only two icons.
Anyway, you don't say what power op-amp you used.
Give us a clue.
And you can try the inverted Gainclone, maby that's the problem.
Or circuit layout.
Do you have the psu caps near the chips?
My Gainclone is not upfront...
 
overmind

overmind

Member
Joined 2002
geocities.com/overmindxx/
Re: it may be dense around here...

janneman said:
Hi Yeo,

You had me worried there for a minute! "Singing" most of the time is used to indicate oscillations. Glad yours is OK!

Jan Didden
Click to expand...

It is not "singing", but performing nicely. :cheerful:


carlosfm said:
...but have you posted a picture?
I can't see anything, only two icons.
Anyway, you don't say what power op-amp you used.
Give us a clue.
And you can try the inverted Gainclone, maby that's the problem.
Or circuit layout.
Do you have the psu caps near the chips?
My Gainclone is not upfront...
Click to expand...





I have problem uploading the pictures, I linked them from Pbase. Anyway, I tried attach the pictures again. The IC I am using is LM3875.

Regards,
SW Yeo
 

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overmind

overmind

Member
Joined 2002
geocities.com/overmindxx/
fedde said:
Wowie, from which planet are they ??? ;)

Nice.

1. Try swinging instead of singing
2. Try the inverting configuration WITH an appropriate resistor on the +input. (621 k in your config)
3. Try more gain. (eg. 20 k <-> 621 k)

Fedde
Click to expand...

Swinging - learned :yes:
I just wonder what is effect of gain or the level of feedback on the sound for this amp. Will try to increase the gain.



karma said:
looks great;) . your website is still down:( o now its up;)


how hot do thay get?
Click to expand...


geocities - free web hosting, there is a limitation of web traffic of the website. It is free, what to do.

How hot they depand on the type of music is being played. If I am listening to pop with lots of bass, then it get a bit warm. For Jazz and classical, it will take about one or two hours of operation before a slight temperature rise can be felt with my hand. Of course, it will depend on the volume/output level. BTW, I am using the amps with Proac 2.5, which is not really a difficult load for the amps.

Yeo
 
overmind

overmind

Member
Joined 2002
geocities.com/overmindxx/
Re: Polarity of Electrolytic

digi01 said:
Good job!! The inside structure is very compact ,I like it :)
Click to expand...

Actually, the mounting hole of the IC was drilled in the centre which is not too good. This make the construction cramped with parts on one side, and the other sider with much space. The leads of the components were not trimmed. The construction of the amp circuit will look better if the above two points were done correctly.



Panelhead said:
The drawing attached has the polarity reversed on one of the 1000 ufd filter caps.
Have you tried the inverting input topology.

George
Click to expand...


I have yet to try the inverting configuration. I will try this and increase the gain to 21x and report back. However, I am quite busy for the coming week, thus this will take some time.

Thanks & Regards,
SW Yeo
 
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