ruffrecords

Re: Impedance formula of a SRPP
« Reply #20 on: August 06, 2016, 03:46:41 AM »
Of all the twin tube topologies, the SRPP does tend to introduce more dstortion tan others (such a s the mu follower) but its great strength lies inits drive capabilty. Combined with a pior gain stage and some negative feedback it is capable of excellent results. Check out this design of mine:

https://drive.google.com/file/d/0B_n67A1hN3qtelg2R21Xa0dIbVk/view?usp=sharing

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


johnheath

Re: Impedance formula of a SRPP
« Reply #21 on: August 06, 2016, 05:01:10 AM »
PRR: I like that explanation and I agree with you completely that on the Internet … opinions flow in all directions.

Ian: Just as for the SRPP I have a very much similar design but without the FB. However the 100k resistor is a question mark to me (i.e not knowing)… do you use that prior to the OT? I recall that you, in some designs, use the mentioned Sowter 5069 as an OT?

Best regards

/John
Nothing is impossible - It just takes some more time

ruffrecords

Re: Impedance formula of a SRPP
« Reply #22 on: August 06, 2016, 06:06:48 AM »
PRR: I like that explanation and I agree with you completely that on the Internet … opinions flow in all directions.

Ian: Just as for the SRPP I have a very much similar design but without the FB. However the 100k resistor is a question mark to me (i.e not knowing)… do you use that prior to the OT? I recall that you, in some designs, use the mentioned Sowter 5069 as an OT?

Best regards

/John

The 100K is there just to make sure there is a dc path to 0V for the output capacitor when there is no transformer connected.

Yes I have mentioned the Sowter 5069 (two posts back!) but I would recommend using s 2;1 step down transformer if you want to drive a 600 ohm load. If you only have 10K loads then the Sowter will be fine.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

johnheath

Re: Impedance formula of a SRPP
« Reply #23 on: August 06, 2016, 06:15:06 AM »
Thank you Ian. I saw your post about it, but I was asking about the 5069 since I have a couple of them at home hoping to find a good use for them.

Regards

/John

Nothing is impossible - It just takes some more time