Hamptone question. a real quicky

i'd like to put an output "fader" between stage 2 and the output tranny. what's an appropriate value? 10k??

Not a good idea. This fader will, unless it is at the top of its travel, introduce a resistance between the output driver stage and the transformer. This means that as you attenuate the signal with the fader, you will also increase the output impedance of the device. With a 10k fader at a 'low' position, you would introduce say 9k between the output driver and the transformer. That makes a really crappy output stage with a very high output impedance. Why do you want a fader there anyway? Is it because you are using a stepped switch between the two amplifiers and you'd like a continuous 'trim' adjustment between steps?

Bjorn

I think you need a T pad... but not sure.

Hey Raf!

Forgot what a T-pad is...if I ever really knew what it was anyway...

You could have one of them balanced pad things on the output, but it needs to keep the output impedance fairly constant. You can cheat, too. I think the manley varimu has one variation where this pad is just a dual 1k pot; should work fine as long as you assume there's no 600Ohm inputs about.

Why do ya want that fader, Al? Are you looking to drive the output stage into distortion for 'colouring' as well?

Bjorn

slightly OT
but ... close enough :wink:

Scott may have some kits that are un-spoken for,
both tube and FET kits.

We now have the next run in stock (both HFJP2 and HVTP2), and have shipped out all prepaid orders, and to people on the waiting list. This
still leaves a good number of them left.

Click to expand...

price is a little strong for me to join in but I'm sure some of you will give these kits a second look.
http://www.hamptone.com/newkits.htm

[quote author="Bjorn Zetterlund"]Why do you want a fader there anyway? Is it because you are using a stepped switch between the two amplifiers and you'd like a continuous 'trim' adjustment between steps?Bjorn[/quote]

i want distortion without having to attenuate with another device before PT.

this was discussed a bit in another thread, replacing one of the resistors to control the distortion in the circuit. It wasnt a master volume though, it might have been on one of of the biasing resistors on the fets, I dont remember, if you do a search you should be able to turn it up, it was discussed here.

dave

Hey, I just scored a few of those monocors LTR110s...okay for what u mentioned right butta?

Nice

coo, like so?:



muchogracias

remove the 1k resistor and ground pin 3 of the x-former.
you need a cap on your output to keep dc off the x-former.
(since you are using a single supply.)
try 4 to 10 uf at 50 volts.

too good - u know pics do it best :thumb:



the above i was thinking of using long side the 16 chan psv summer box im near done...

Ta

hey...

Right, finally got audio out from the above config but ended up having to ground pin 7 too (no audio out otherwise) - does this make sense as im wondering if I've made a error in the pinning.

2, 4 and 5 were left floating...however, i tried dif pin setups (like audio goin to pin 2) and was still gettin audio out - seems a few ways u can wire these lil tingz!!

cheers :thumb: