Help with 1626 PSE Amp needed

[hotzinger]

Hi everybody!

I just finished my latest project, a 1626 PSE Amp.

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

I used a 47µF cathode C, though.

After a while of listening, I thought, that the bass is a little "thin".

Looking at the bode-plot I discovered the following:

What are your suggestions to improve the output?

Thanks for your input.

Holger

 

[hotzinger]

sorry, forgot to post the bode plot

WEll, here is the above mentioned bode plot....


What do you think?

 

[benny]

the very first thing i noticed was that there is no interstage coupling caps. And there is no ground resistor between first and final stage.

the coupling cap and ground resistor before a stage form a highpass filter with a -6bD/octave slope with a -3dB point calculated by f=1/(2*pi*R*C)

R and C represent values of these components... i'll let you guess which one represents the coupling cap and which one represents the ground resistor.

you can also use a bit of neg feedback to help flatten out frequency response.

also try using a tone control. something simple like a baxandall tone circuit would take you not much time to put together, and will give you plenty of control over frequency response.

cheers

 

[audiophilediyer]

Hi,
Hammond 125E can't give you enough flat response, no air gap between EI lamination, try 125ESE.

Here's a new info about 1626, distortion curve,

http://www.audiohobbyist.com/projects/1626.htm

cheers,