OT: Bass preamp clipping problem

[rubberlips]

G'day guys,

I have a question about a bass preamp circuit that I'm having trouble with.
Here's the part of the schematic that's giving me problems
http://us.f2.yahoofs.com/bc/421697a8_8ab/bc/bass_preamp.jpg?bf3wpFCBOjOb9UHG

It's clipping the top and bottom of the wave when I feed a sine wave in when you turn the treble control up on pin 6, much like it's hitting power rails, however the voltage is only 2V pp. The supply rails are +/-15V.

From what it looks like it's a slew rate problem. When I change the NE5534 to a TL070, it's not clipping anymore, but the wave does change shape (the bottom end seems okay, the top end is limited slightly, but it's still a sine wave). Maybe it's got more to do with the frequency I'm feeding in, after all it's supposed to be a bass amp.

Also, the pins 5&8 seem to be mixed up on the board and the schematic. Which is correct for the DC offset control?

One other thing about the offset control I'm not sure about. On the PCB, the 22K resistor goes to +15V, however on the schematic it's says it goes to signal ground? Which would be correct?? I'd take it the PCB would be correct??

There's a few boards for this bass preamp (preamp stage, equalizer and compressor), and I think it's distorting in a few spots, so I'm trying to weed out the problems one at a time

Any suggestions??

Cheers

Pete

[rubberlips]

bump,

Anyone got any ideas??

Or does anyone know of a good bass preamp circuit to make with an preamp, EQ section and compressor??

Cheers

Pete

[Rob Strand]

I'd like to help but the link didn't work for me (spent a bit of time trying to huntthe pic down through yahoo but with no sucess).

[rubberlips]

Thanks Rob,
Must be something stupid with yahoo - did I say yahoo was stupid?? :shock:
Here's the URL again, if it doesn't work let me know and I'll have to find another place to put it
http://us.f2.yahoofs.com/bc/421697a8_8ab/bc/bass_preamp.jpg?bfq_vGCB2.be9UHG

A couple of guys have been talking about storing pictures. Anyone know where that free server is??

Cheers

Pete

[Mike Burgundy]

Still doesn't work. Remote linking isn't possible from Yahoo...

[Rob Strand]

I tried to understand what's going on with the yahoo link but I couldn't work it out.   There's us.f1.yahoofs.com...  and us.f2.yahoofs.com - got nowhere with  either.

I have a feeling a link to a html page would be OK.