You should check the salas regulator specs and how to change it.
Whit this mains you should get higher volateges.
Whit this mains you should get higher volateges.
could be fun to try the caps output..
but i must also say,,,my Lundahl 2745 trafo sound very very fine
but it is diy ,,and it is fun to try things out
but i must also say,,,my Lundahl 2745 trafo sound very very fine
but it is diy ,,and it is fun to try things out
I found a resister load smoother than a CCS, but as said it lacks definition. I liked the LL1660 best of all - it had the smoothness of the resistor with more clarity. I always found CCS loads a trifle sharp - couldn't get rid of an edge that annoyed me.
Hello
Can you please tell me ,,,can i get more gain out of my Lundah 2745 trafo--
I have it wired Alt.R 5.6 to 1
will Alt.Q 5.6 to 2 give more output ?
the only thing i know is...is the different wiring give different impedans at output..low on Alt.R
My Doede dac give only 1.4v out...so i will like a bit more gain
Best Bjarne
Can you please tell me ,,,can i get more gain out of my Lundah 2745 trafo--
I have it wired Alt.R 5.6 to 1
will Alt.Q 5.6 to 2 give more output ?
the only thing i know is...is the different wiring give different impedans at output..low on Alt.R
My Doede dac give only 1.4v out...so i will like a bit more gain
Best Bjarne
If you connect the LL2745 for 2.8:1 (5.6:2) you will get twice the output, but at about four times the output impedance. As long as your power amp has a highish input impedance (~100K) you shouldn't notice that part of the change.
Andy, is it ok to ask you to share which 'types' you have tried and also how they were constructed (physically).
I've found pimm self bias rev5 built on veroboard, then RF enclosed, using Gary's layout and suggested parts to the equal in every respect, and then some, compared with an M3 cored unit which was well suited for the application (Hi BudP, - still love ya bro - second best - and I think Bud will tell you the same) and far surpassing LL and Lancroft double C core chokes, and LL1660 for that matter but only in 1:1 (0.9?), all gapped accordingly.
IMHO the right CCS is cheaper, takes less foot print, weighs less and most importantly sounds very very well.
I did find adding 500R CC series to plate worked well, YMMV, as it does. Also the opportunity exists to take output from the 'mu' node which should approximate (pimm rev5) 200 Ohms plus the XC of the coupling cap at said frequency - or simply direct couple. Don want large Rk and bypass BS.. use a split or stacked supply, anyway - I digress.
Used to think caps sucked, still kind of do.. but potted (get creative) tin foil in poly sound pretty good to me in larger values 2uF etc - phase shift at LF and not just LF pole. Used to dismiss the idea, then tried it and now its more about whatever works. And it works well. YMMV.
DIY Hifi is not a registered religion (life is shorter than what the guy had in mind when he said 'life is short').
Have AVO matched pairs E280F from factory 100 pack, if of interest. PM for details or check sceglar at ebay.com from .. tomorrow, or the day after, lots of other tubes too.
Best to you all,
Shane
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Yes, I've had a 4P1L line stage in my system for about 9 months. I have developed some raw filament supply boards to go with Rod Coleman's filament regulators, as I'm using these and use my shunt regulator kit on the high voltage. I need to do a bit more experimenting with output transformers, to see which one I prefer, but time is short....
Kevin
remember to try LL2745 as output trafo..by me it sound super
Have just wired it 5.6::2 give me more gain.
What will be best in theoretical way......technical way ,
to wire 5.6::1 or 5.6::2
Low output impedance vs higher gain
I like to know more of the Technic behind my LL2745
Best Bjarne
remember to try LL2745 as output trafo..by me it sound super
Have just wired it 5.6::2 give me more gain.
What will be best in theoretical way......technical way ,
to wire 5.6::1 or 5.6::2
Low output impedance vs higher gain
I like to know more of the Technic behind my LL2745
Best Bjarne
Hi Every DIY 4P1L...
Had a listening session yesterday, with three Persons who have followed the development of my 4P1L.
We was listening to my newly modified Rod Coleman ver 5 boards, with Oscons and Mills MRA-5.
PS! I'm on ver 1, so Oscons which are 1000uf/16v will not survive on a 15ohm 4P1L.
I Also had made better improved AC/DC board with 32800uF Panasonic FC which gives
a much lower Ripple value.
And the 100 million question is, can "we" still improve things in our belowed 4P1L.
And the answer is, Yes we can. This quite cheap "upgrade" was a remarkable step up,
and what chocked me most was the clarity and quietness in between the notes 🙂
Now I think I would be very costly, to make any further improvements in my Caps based version of my 4P1L.
/Best Michael
Had a listening session yesterday, with three Persons who have followed the development of my 4P1L.
We was listening to my newly modified Rod Coleman ver 5 boards, with Oscons and Mills MRA-5.
PS! I'm on ver 1, so Oscons which are 1000uf/16v will not survive on a 15ohm 4P1L.
I Also had made better improved AC/DC board with 32800uF Panasonic FC which gives
a much lower Ripple value.
And the 100 million question is, can "we" still improve things in our belowed 4P1L.
And the answer is, Yes we can. This quite cheap "upgrade" was a remarkable step up,
and what chocked me most was the clarity and quietness in between the notes 🙂
Now I think I would be very costly, to make any further improvements in my Caps based version of my 4P1L.
/Best Michael
4P1L Gen1
Hi Michael,
Thanks for sharing your feedback. Very useful to all I think.
I agree with Shane's comments about the CCS load. In fact the mu-follower configuration using the gyrator load sounds very nice to me. Particularly as the 4P1L is run at 20mA or more, the DN2540 is well placed here to do the job.
There are some minor upgrades you could do to your Gen1 design if you're interested in:
1) Cascode the DN2540
2) Replace the voltage reference with a cascoded pair of LND150. This will improve the HF response
The overall PSR and HF response will be better. I have done this with my latest implementation of the 01a preamp here. Running depletion FETs at less than 10mA is not ideal, hence the use of the JFET. I should have also replace the top DN2540 with a pair of LND150 in parallel as that will improve the PSR to above 100dB. However, it sounds really well and is very very quiet as is. So won't change it.
Hope this helps
Ale
Hi Michael,
Thanks for sharing your feedback. Very useful to all I think.
I agree with Shane's comments about the CCS load. In fact the mu-follower configuration using the gyrator load sounds very nice to me. Particularly as the 4P1L is run at 20mA or more, the DN2540 is well placed here to do the job.
There are some minor upgrades you could do to your Gen1 design if you're interested in:
1) Cascode the DN2540
2) Replace the voltage reference with a cascoded pair of LND150. This will improve the HF response
The overall PSR and HF response will be better. I have done this with my latest implementation of the 01a preamp here. Running depletion FETs at less than 10mA is not ideal, hence the use of the JFET. I should have also replace the top DN2540 with a pair of LND150 in parallel as that will improve the PSR to above 100dB. However, it sounds really well and is very very quiet as is. So won't change it.
Hope this helps
Ale
@Michael:
I quickly simulated this in LTSpice. If you want to try this, I think is worth doing:
4P1L Siberian Gen1 upgrade | Bartola Valves
Ale
I quickly simulated this in LTSpice. If you want to try this, I think is worth doing:
4P1L Siberian Gen1 upgrade | Bartola Valves
Ale
Hi Ale.
I have cascode the DN2540, So my Schematic is very close to this "new" one
besides the LND150 part.
Frankly I'm so happy with the sound of the my 4P1L, that I'll leave it "AS IT" for
at least a couple of months.
Thanks anyway for your suggestions.
PS! Ale have you tried the "ANDY's 4P1L PSE" with your 4P1L. I'm seriously consider
to build this as my next "big" project...
I have a "tons" of questions, but I'll leave them to Andy.
/Michael.
I have cascode the DN2540, So my Schematic is very close to this "new" one
besides the LND150 part.
Frankly I'm so happy with the sound of the my 4P1L, that I'll leave it "AS IT" for
at least a couple of months.
Thanks anyway for your suggestions.
PS! Ale have you tried the "ANDY's 4P1L PSE" with your 4P1L. I'm seriously consider
to build this as my next "big" project...
I have a "tons" of questions, but I'll leave them to Andy.
/Michael.
Hi there - if you build my PSE 4P1L I'm pretty sure you'll like it. It's a bit special on things like vocals - very transparent and lifelike. I listen to a lot of vocals and opera so it's a constant pleasure. Don't cut corners, though, it needs to be fully optimised. Andy
Attachments
Finally going to start assembling a line stage with this tube.
I know I can go ready made with the LUNDAHL transformers but wonder if one of the boffins here could give me some advice.
I would like to send some business to Dave Slagle and have him wind an output. If one was to go custom is there a best configuration?
I do not need, or want, high gain. Would prefer low output impedance since my above-500 hz amps have a 10K input impedance, the rest are 50Khz and above.
Wondering if someone has advice to offer for such a thing? I know little about how transformer specs interrelate with each other so HELP is appreciated!
Take care,
I know I can go ready made with the LUNDAHL transformers but wonder if one of the boffins here could give me some advice.
I would like to send some business to Dave Slagle and have him wind an output. If one was to go custom is there a best configuration?
I do not need, or want, high gain. Would prefer low output impedance since my above-500 hz amps have a 10K input impedance, the rest are 50Khz and above.
Wondering if someone has advice to offer for such a thing? I know little about how transformer specs interrelate with each other so HELP is appreciated!
Take care,