MPP

[Joachim Gerhard]

I made a circuit like that.
Lets see if i can find the diagram.

 

[as_audio]

Also, AS. I want to see if I could get Joachim hooked to the idea of how far could one push the single-supply, single-ended concept.

The technician in me also like the symmetric and nice concept. But, is it good or just visual nice for the technician?

Cheers,
Mogens

You can do single ended without coupling caps, but need a split supply.

 

[mkc]

Hi guys,

AS, but not with DC wall plug surely?

Thanks Joachim, I have a "back of the napkin" drawing here too. But, how could could it actually be made? that's my thinking?

Also, Joachim. check out the girl in my link. If only the general hifi enthusiast has as much happiness towards music.

Cheers,
Mogens

 

[as_audio]

So I have to ask what is a dc wall plug?

 

[mkc]

Hi AS,

Sorry, for not being clear. Just a standard wall-plug which provides DC voltage. I have a few here. Actually, I haven't got many AC ones, beside the ones I have made so.

Cheers,
Mogens

 

[as_audio]

I have not seen a dc wall outlet in my life.
AC mains is common here for 70+ years..

Edison would be happy with it.

 

[mkc]

Hi AS,

I see the confusion. A langue barrier on my part perhaps?

Wall-plug == transformer or even switch mode PSU that plugs directly into the wall-plug.

Sorry for the confusion,
Mogens

 

[Joachim Gerhard]

Yes, that girl is in the groove.

 

[as_audio]

Hi AS,

I see the confusion. A langue barrier on my part perhaps?

Wall-plug == transformer or even switch mode PSU that plugs directly into the wall-plug.

Sorry for the confusion,
Mogens

Seems I was right in the first place.
So if you plug a transformer in the ac wall outlet anyway, why don't you chose one which fits the need?
The price of it is considerably less than the price of the RIAA.

 

[mkc]

Hi AS,

Sorry if I misunderstood you. What I was thinking of was a generic one which could be had with all approvements and build in a black block. Perhaps I'm not expressing myself properly. Sorry about that.

I would like to use something generic that had all the approvements so I could sleep well if my sons friends build an RIAA here and took it home and plugged it in.

Cheers,
Mogens

 

[Joachim Gerhard]

This circuit uses a wallwart as i call it :http://nixiekits.eu/Downloads/SPA_Aufbauanleitung.pdf
They squeeze out more voltage with a cascade ( voltage doubler... ).
There is even a tube in there.
I build it for fun and it works.

 

[Joachim Gerhard]

AC adapter - Wikipedia, the free encyclopedia

 

[31697B]

JG,

Will you be doing a power amp... about 200-250W/8 would be nice from you.


THx-RNMarsh

 

[Joachim Gerhard]

I really NEED a high power amp.
It is not my forte though.
I designed a Class A amp that is said to sound good.
It has some Class A/B leverage upwards.

 

[Joachim Gerhard]

You see it in the rack on the bottom.
On top is the fitting preamp.
Both prototyps.
The amp drove the refurbished Ohm F just fine.

 

[Joachim Gerhard]

Both, amp and preamp, use Lateral fets at the output, output from the drains and not the sources.

 

[Joachim Gerhard]

The output impedance is low ( not very ) due to current feedback from the output.
This amps are not so much about low distortion but they are stable on any capacitive load and have high speed into the MegaHerz.

 

[Joachim Gerhard]

I succeeded to make a lineamp out of circuit post 10013 with the help of AS and Frans.
Offset is trimable and stable plus-minus 1mV.
This without any matching or thermal coupling, good.
In this case lowest offset also brings lowest distortion.
I learned from Scott Wurzer that this is a good thing.
More information soon.

 

[Joachim Gerhard]

For Frans :http://lib.ugent.be/fulltxt/RUG01/002/033/143/RUG01-002033143_2013_0001_AC.pdf

 

[Joachim Gerhard]

Also for Frans or anybody interested in settling time :http://www.circuitsage.com/a2d/optPM.pdf