I used to ask Patrick 2 years ago with questions but recently haven't heard from him. Hope, he is doing well.
In his reformed Jadis 300B PSE, he used Hammond 2k5 impedance. Can I use Edcor CXSE25-1.25K impedance so I can remove some of the parts on the output transformer? Even Hammond has 1.25k impedance OPT but he picked 2.5k.
Patrick's website: jadis-300b-reformed
In his reformed Jadis 300B PSE, he used Hammond 2k5 impedance. Can I use Edcor CXSE25-1.25K impedance so I can remove some of the parts on the output transformer? Even Hammond has 1.25k impedance OPT but he picked 2.5k.
Patrick's website: jadis-300b-reformed
Thank you both,
I emailed him two weeks ago about this OPT but didn't see the respond until I saw euro21's link. Patrick was a wonderful man who could answer and explain more than I needed to know. RIP Patrick Turner!!!
I emailed him two weeks ago about this OPT but didn't see the respond until I saw euro21's link. Patrick was a wonderful man who could answer and explain more than I needed to know. RIP Patrick Turner!!!
If the Edcor has multiple output taps as an option like the one in this schematic, just re-label as needed for the correct impedance ratio and make sure it matches your speakers. Plus, tubes are super friendly to output transformers. I saw one guy test a PP circuit with a 10 to 1 ratio of impedances and output was +/- 25% that entire extreme. Distortion went up and down a good bit but was never really out of hand... you have have flexibility. Especially if the Edcor offers multitap output as a build option. Remember it's just a ratio, can you match the ratio of this transformer to what you need?
Edcor only offers 8 ohm while the NFB on this schematic connects to 16 ohm. This is what I don't know how to connect to 8 ohm.
Actually, since you're intending to use a 1K25:8 transformer instead of a 2K5:16 transformer, the voltage output is the same, so just connect the speaker, Zobel, and feedback to the same place.
All good fortune,
Chris
All good fortune,
Chris
While I don't see a multi tap they do offer a ratio winding. 4, 8 or 16. You can match the ratio for sure... unless you absolutely need the multi tap for your circuit. You can also get a quote for a custom wound unit with a tapped output. They do that. I have several amps with their transformers and they are very good. Especially for the cost. <-That. The only ones I have better are 1950s Chicago Transformer which are simply gems at this point. Basically what I am saying is 2.5k to 8 is the same as 1.25k to 4. So take the 1.25k and put an 8 on it is the same transformer as in the schematic. Adjust feedback as needed, but it doesn't need changed. Quick glance 4 output taps, youll have to tweak something, the point is, you can and it's only a little work. And the tolerances are really forgivable. Just think about it a bit, decide what you want and get on it. Edcor has like a 3 month wait, so you have time to consider...
Follow up, Edcor for me is showing 4, 8 and 16 output options as of 6/26/2021. Not just 8. And they do custom wind. 3 month lead time.
[QUOTE Patrick was a wonderful man who could answer and explain more than I needed to know. RIP Patrick Turner!!![/QUOTE]
I could not help express sorrow for such great loss--RIP Mr. Turner. I utilized your reworked Quad II with excellent results. You were indeed a noble minded gentleman to the very last moment. Your numerous contributions were all so detailed and informative. You even complied and provided a thorough and informative record of the stages of your treatment all so meticulously graphed and detailed for the male audiophiles to be aware of--what exceptionally altruistic persona you remain as you are amidst us. Thank you so very much for your work and the example you left for some of us to follow.
Seraph
Ps. forgive me for having rattled off topic
I could not help express sorrow for such great loss--RIP Mr. Turner. I utilized your reworked Quad II with excellent results. You were indeed a noble minded gentleman to the very last moment. Your numerous contributions were all so detailed and informative. You even complied and provided a thorough and informative record of the stages of your treatment all so meticulously graphed and detailed for the male audiophiles to be aware of--what exceptionally altruistic persona you remain as you are amidst us. Thank you so very much for your work and the example you left for some of us to follow.
Seraph
Ps. forgive me for having rattled off topic
For 2 tubes in parallel 1,25K is about right without manipulating the secondary taps , as 1 tube require 3K - 3K5 .
Best for power or distortion, or as you say a "compromise"?
We're back to the 3K versus 5K discussion for a single 300b. I'm in the 5K camp because I don't need the power.
Andy, as you can see in the attached picture, the 1k5...1k65 load is the "best", where the loading alteration (the loudspeaker is not constant load depending of frequency, so its transformed value to the primary also changing) causing as small as possible THD variation.
So the single 300B the 3k..3k3 range behaves similarly, so it's the - all-round - "best compromise".
I also regularly use 5k transformers in my 300B amps for the lowest distortion (but with A2 capable driving, so 10W is available).
So the single 300B the 3k..3k3 range behaves similarly, so it's the - all-round - "best compromise".
I also regularly use 5k transformers in my 300B amps for the lowest distortion (but with A2 capable driving, so 10W is available).
Attachments
RIP Mr. Patrick! A tremendous loss of wisdom.
Please folks, archive his website. In his memory. It's something he recommended during his final years in his emails, before finally leaving us.
I mean Edcor only offers 1 option which I only need 8 ohm while Hammond has 16,8, 4. I have seen a few other designs used 1.2k so I thought I can use the Edcor to match with my Edcor PT and eliminate some parts on OPT.
Look like euro21's simulation is matched with Patrick's design. I think I will stick to Hammond 1627SEA OPT, it's not that bad for few more parts.
If anyone needs to download Patrick's website, you can use HTTrack Website Copier app. Just open the app, copy the main link and paste to download. Thank you Patrick for all the detail info.
Look like euro21's simulation is matched with Patrick's design. I think I will stick to Hammond 1627SEA OPT, it's not that bad for few more parts.
If anyone needs to download Patrick's website, you can use HTTrack Website Copier app. Just open the app, copy the main link and paste to download. Thank you Patrick for all the detail info.
At the request of Alashikata, this is the another (380V, 80mA) simulation.
IMHO the most neuralgic point of this layout not the operating point, but the OPT.
The 150..200mA static current and about 25W estimated power requires big core and heavy copper wires, so it's a costly game, if you want satisfying LF and especially HF behaviour.
IMHO the most neuralgic point of this layout not the operating point, but the OPT.
The 150..200mA static current and about 25W estimated power requires big core and heavy copper wires, so it's a costly game, if you want satisfying LF and especially HF behaviour.
Attachments
Thanks again euro21,
The Edcor PT I currently have B+ at 445v without load so I am assume it would fall between 380-400v. Each PT has 250mA so I guess it's enough for monoblock. Losing few watts is fine, sound qualify is more important.
The Edcor PT I currently have B+ at 445v without load so I am assume it would fall between 380-400v. Each PT has 250mA so I guess it's enough for monoblock. Losing few watts is fine, sound qualify is more important.
Thanks for the files 
I just installed LTSpice to play around. The software is little bit confused but not bad.
I just installed LTSpice to play around. The software is little bit confused but not bad.