Ela-M 251 Body from Aliexpress

[garp]

I can't say that i have no clou . I choosed the M23 series mainly because of the inflating prices of the antique amphenol tuchel 7 pins (available at Binder but badly distributed in Europe). And now i have problems finding Binder M23 i need for future projects (

 

[egroys]

175V is perfectly, that should deliver about (x 1.41) 245V DC, not rippled. Theoretically you can use every transformer above 120V AC secondary for the plate Voltage. You have more than enough Voltage after the D1-D4 diode bridge for the ripple the B+Plate down to 120 V DC, what is needed as Plate Voltage for the Mic. Might be possible that you want to decrease the R1 and R2 75K Ohm Dropresistors to 50k Ohm used for 175V instead of a 200V AC secondary output Transformer. But not really necessary. There is B+ R4 trimmer with 250k is for adjusting properly the 120V DC. The secondary 9V AC is ideal for generating the LM317 regulated Tube Heater/Filment Voltage down to 6.3V DC. If Poctops included "L" PSU - PCB is too big / high or to broad for the Retro Case, mount it with two bottom mounted 45 degree bent metal angles, diagonal, no disadvantage.

Have you (or anyone) used the Retro with Poctops L PCB? If so, can you send any photos of how you go it to fit? With the caps sticking out, it's feeling a bit sketchy and I am curious what the best way to make it work is. Please and thank you!!

 

[HerbertR]

Have you (or anyone) used the Retro with Poctops L PCB? If so, can you send any photos of how you go it to fit? With the caps sticking out, it's feeling a bit sketchy and I am curious what the best way to make it work is. Please and thank you!!

Hi, I used not the Retro II case/PSU with 251 PCBs. If the size of the Retro is the same as my Retro I case as in the picture, it might be a challenge to fit it. The L-shaped Poctop PCB is about 100mm x 140mm with 100mm x 40mm "Transformer cutout". This means that if the PCB was used rotated 90°, it would fit in the Retro II case. But then there would be too little space left to mount the power transformer even if it was also rotated 90° because the TX Block measures 50mm x 50mm incl Windings and is 40mm high, with the TX bracket for the moutings screws it measures a total length of 80mm. The Retro II case is much taller at 90mm and so you could possibly mount the TX on the side of the cover case. But then you might get the small chance of transformer interference. Regards

 

[egroys]

Hi, I used not the Retro II case/PSU with 251 PCBs. If the size of the Retro is the same as my Retro I case as in the picture, it might be a challenge to fit it. The L-shaped Poctop PCB is about 100mm x 140mm with 100mm x 40mm "Transformer cutout". This means that if the PCB was used rotated 90°, it would fit in the Retro II case. But then there would be too little space left to mount the power transformer even if it was also rotated 90° because the TX Block measures 50mm x 50mm incl Windings and is 40mm high, with the TX bracket for the moutings screws it measures a total length of 80mm. The Retro II case is much taller at 90mm and so you could possibly mount the TX on the side of the cover case. But then you might get the small chance of transformer interference. Regards

Thank you, that's good to know. I'll see if I can pull it off, otherwise I will have to get a TPS100!

What mic are you using the Retro II for?

 

[HerbertR]

Thank you, that's good to know. I'll see if I can pull it off, otherwise I will have to get a TPS100!

What mic are you using the Retro II for?

It's a Retro I case and I use it with Oliver Archuts C12 "self cathode biased" version circuit, Siemens Halske ECC801S, 3U C12 TX and an AKG C12VR Nylon capsule. I have a lot of unused components lying around. The build was a kind of "Restl' verwerten'" we would say in Austria. The nice looking mic housing is from Ali, but feels a little bit cheap, the green Tube is made from Alu and therefore feels slightly hollow.
But sound is pretty nice, well-behaved, clean, transparent and "right" like the source in real in front of the mic, like you would expect from a CK12 nylon AGK capsule in C414 with a homeopathic dose of dope. And not like a brass CK12 from all the well-known boutique manufacturers. But that's a bit off topic now...