My SSS 001 As Built, Corrected Schematics

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mcinku
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Re: My SSS 001 As Built, Corrected Schematics

Post by mcinku »

Well I can't tell you how this step filters sounds like yet but I will in a few days... hopefully.
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mcinku
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Re: My SSS 001 As Built, Corrected Schematics

Post by mcinku »

OK finally this weekend I had some time to test this amp and I have to say there is something different about this SSS amps.
I also have one issue which so far I was not able to fix....Hi pass filter doesn't do anything. I checked and rechecked everything but still I can't make this work.
:roll:
Synchu
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Re: My SSS 001 As Built, Corrected Schematics

Post by Synchu »

Hey Mirc,
Did you manage with it? Any samples? :)
Niki
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mcinku
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Re: My SSS 001 As Built, Corrected Schematics

Post by mcinku »

OK just have to share a few things about the amp...
...the amp sounds awesome. I think I never played an amp which sounds so tight and precise but still with a lot of content.... can't find any better words for it.
However I have to report that Hi filter doesn't do much... at least on my amp. I checked my wiring and I think everything is fine. David will check if his amp is doing the same. If this is the case, I guess I will have to change #001 filter design to #002 filter design.
I just want to let everybody know before somebody starts to build an amp based on my layout.
tictac
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Re: My SSS 001 As Built, Corrected Schematics

Post by tictac »

Looking at the filter schematic on the first page of this post, that 150k in series with the capacitors to ground would seem to block any effect those caps would have on the signal...

You could try removing that resistor and see what happens...

I've used the 002 filter version and it works well, at least to my ears...

TT
Synchu
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Re: My SSS 001 As Built, Corrected Schematics

Post by Synchu »

Good points. I plan to build #02 and wondering (again) what the differences sound wise would be.
Mirc, it will be much appreciated if you can post a sound sample? :)
Niki
tictac
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Re: My SSS 001 As Built, Corrected Schematics

Post by tictac »

Whoops.... :oops: when I said "remove" the 150k resistor....you'd still need to replace that resistor with a piece of wire so that the tone control would actually do something...

I'm sure you already realized that but just in case.... :lol:
wjdunham
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Re: My SSS 001 As Built, Corrected Schematics

Post by wjdunham »

Just for the recored - #001 and #002 are basically the same amp with the exception that #001 has the Tremolo and #002 does not. Mixer circuit, filters, power amp etc... are all the same as are the layouts.

Bill

www.sebagosound.com
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mcinku
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Re: My SSS 001 As Built, Corrected Schematics

Post by mcinku »

tictac wrote:Looking at the filter schematic on the first page of this post, that 150k in series with the capacitors to ground would seem to block any effect those caps would have on the signal...

You could try removing that resistor and see what happens...

I've used the 002 filter version and it works well, at least to my ears...

TT
I will try resistor decade instead of 150k resistor and see how that affects the tone.
...and will report back.

Thanks
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mcinku
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Re: My SSS 001 As Built, Corrected Schematics

Post by mcinku »

Synchu wrote: Mirc, it will be much appreciated if you can post a sound sample? :)
Niki
It will happen one of these days.
:wink:
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mcinku
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Re: My SSS 001 As Built, Corrected Schematics

Post by mcinku »

wjdunham wrote:Just for the recored - #001 and #002 are basically the same amp with the exception that #001 has the Tremolo and #002 does not. Mixer circuit, filters, power amp etc... are all the same as are the layouts.

Bill

www.sebagosound.com
If that's really the case then this schematic which we have here is wrong... or this really isn't #001 amp.
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mcinku
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Re: My SSS 001 As Built, Corrected Schematics

Post by mcinku »

150k resistor to the Hi switch definitely doesn't work... I tried several different values and I think I will end up somewhere between 10k and 20k. When I left the amp I had 15k in there but that might change, after I play the amp a bit more.
I also changed first cap from 100p to 20p... there is almost no difference between 100p and 360p. Last two caps .01uF and .02uF dramatically change the tone of the amp. I still didn't decide, if I like that or not... in a way it's very interesting but it might be to dramatic for some people.

Thanks for the help.
:wink:
markusw
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Re: My SSS 001 As Built, Corrected Schematics

Post by markusw »

I did an LTSpice simulation of the filters as shown in the schematics on page 1 of this thread.

I stepped the hi filter with 20p (green), 100p (blue), 360p (red), 1n (light blue), 10n (pink), 20n (grey) with the low filter set at 390k.

Once I left the 150k at 150k, once I reduced it to 15k.

I also stepped the low filter 82k (green), 150k (blue), 390k (red), 680k (light blue) and 1500k (pink) with the high filter set to 20p.

I think the simulation fits quite well to your observation that hi filter doesn't do much with 150k and also that you don't hear any difference between 100p and 360p even with the 15k. Also it fits to the dramatic change in tone you observed with the 10n and the 20n.

The simulation of the low filter (in fact a high pass) also appears reasonable to me. To my understanding the fc of the "low" high pass filter is defined by the 5n cap and the resistance to ground after the cap.
As there is 168k to gnd already (the 68k/100k voltage divider after the cap) only the lower resistor values (82k and 150k) of the low switch have an influence on the fc of the high pass filter as they act in parallel to the fixed 168k resistance to gnd. As the "output" impedance of the circuit in front of the 5n is a bit above 100k low resistor values of the low switch also reduce the overall signal strength.

I'd go for the filters of SSS 002, just my 2 ct.

EDIT: the inductor was set 900 mH. However, with the 150k there is no difference between 650mH and 900mH. With 15k there is a slight difference. (see next page)
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Last edited by markusw on Sat Mar 08, 2014 7:26 am, edited 1 time in total.
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mcinku
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Re: My SSS 001 As Built, Corrected Schematics

Post by mcinku »

This is grate Markus, thanks...

I did measure RMS voltages with my scope, with different filter values and my measured voltages reflect exactly what you posted here. I think I measured everything at 500Hz, 1kHz, 3kHz and 6kHz
Which SW did you use for this.... I think I need to have it. :wink:


BTW do you have this charts for #002 filters.... I wonder how different it is compared to this.
markusw
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Re: My SSS 001 As Built, Corrected Schematics

Post by markusw »

I did measure RMS voltages with my scope, with different filter values and my measured voltages reflect exactly what you posted here. I think I measured everything at 500Hz, 1kHz, 3kHz and 6kHz
Glad this helpful :-)
mcinku wrote:T
BTW do you have this charts for #002 filters.... I wonder how different it is compared to this.
I posted the charts for the SSS002 filters a while ago in this thread
http://ampgarage.com/forum/viewtopic.ph ... eep#205481
They definitely differ ;-)

mcinku wrote:This is grate Markus, thanks...
Which SW did you use for this.... I think I need to have it. :wink:
You mean the LTSpice switch model?
IIRC I did a model/symbol for a 7PST switch myself.
I can send if you need it.
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