Ship Of Theseus: compatible, interchangeable amplifier modules

[peppennino]

Truly amazing, Mark!!! Two of the input boards are like sea mermaids to me

 

[gary s]

Thanks guys for the VCC voltage - appreciated.

 

[Dennis Hui]

Mark, thank you for these incredible gifts.

Cheers,
Dennis

 

[glenv6]

This is fantastic - Thank you Mark! The PCB houses are going to be busy. And so am I 🤓

 

[Mark Johnson]

Thank you, everybody! I'm very grateful for your kindness. I hope you enjoy mixing and matching output stages with front ends with PSU filters, as much as I have. It's delightfully addictive!

 

[PKI]

Thank you Mark, those look amazing!

 

[zman01]

Great work Mark Johnson! Thank you for your efforts to support the DIY community with these designs. I am sure they will lead to many hours of building, listening, tweaking, and discussions... and of course the enjoyment of the hobby and music.

 

[TungstenAudio]

Torn between moving forward with my plans for M2x front ends IPS6, IPS7 and Cedarburg, and trying more options with my VFET amps.
Guess I should get a Nimitz...
Very sneaky.

 

[gary s]

Hi Mark,

From all the mixing and matching you might have done with all these new options - do you have any personal favorite combination at this stage?

 

[6L6]

Gary - you do know that the answer is always going to be “Whichever I’m listening to at the moment!!”

 

[gary s]

Yeh, you are probably right Jim, but just trying to narrow it down a bit - too many options. Are we sure Mark is not working for Mouser, Digikey, Edcor and the PCB fab houses?

If you were going to do build guides for all of these , you would have a job for life.

 

[Nelson Pass]

Made me google "ship of Theseus".

 

[glenv6]

The ships have sailed and I am onboard the fleet. I ordered Output Chan A and B boards, PSFILT, the Missouri and Bon Homme Richard Input boards from JLCPCB. I went a bit up market, ordering black boards with ENIG plating. I ordered 5 of each, so if I decide to offer up the extras, I will do so on this thread for cost + shipping (these were on the pricey side) at a later date. If you're going to build this project, please don't wait for me, I don't know when this will be.

My primary goal with this project is for a balanced input, so while I ordered the Bon Homme board, I will order parts to stuff it later. Besides, I already have the Dreadnaught and Bulwark kits to checkout too.

And of course there are parts shortages to contend with, so I couldn't get everything in one order from Mouser. Here's a list of parts Mouser doesn't have, or where I had to go with the recommended substitutions. I have yet to look elsewhere for the parts Mouser is out of, and I haven't yet started combing through datasheets to look for viable substitutions. That's my next step.

Output
-R5 2.08K 2.08K ohms (1%) 0.25W 603-MFR-25FTE52-2K05
-RV1 1 200K 200 Kohm trimpot multi-turn Zig-Zag pinout !! 858-67YR200KLF

PFILT
-10K 10K ohms (1%) 0.25W metal film resistor 603-MFR-25FBF52-10K
-ICL1 1 CL60 inrush current limiter ICL "thermistor" disc 527-CL60
-C1 - C6 6 1000U 1000 uF 50V electrolytic super low ESR 667-EEU-FM1H102B OR 667-EEU-FR1H102
-ZD2 1 1N4742A 12V Zener 1 watt 78-1N4742A
-RL1 1 DPDT relay 24V coil (!!), 653-G2R-24-DC24 OR 655-RTE24024F OR 651-2961192 (last option is available)
-PANEL_SW 1 DPST switch 629-GRSV-4021-0006 OR 629-GRS-4021-0032 (last option is available)

Input - Missouri
-C1 1 100P 100 pF capacitor 100V or more NP0/C0G ceramic 594-K101J15C0GH5TH5
-C5, C12 2 470U 470 uF 50V electrolytic low ESR 647-UHD1H471MHD OR 710-860080678019 OR 871-B41858C6477M (last option is available)
-C7, C8 2 10U 10 uF film capacitor 50V or more 871-B32522C106K189
-C16, C18 2 0.1U 0.1uF film capacitor 100V or more 871-B32529C1104M000
-U1 1 LME49720 TI dual opamp DIP-8 926-LME49720NA/NOPB

 

[TungstenAudio]

Good information to have here in this thread.

 

[Mark Johnson]

Good on ya, @glenv6! Black with ENIG gold will be truly beautiful, but the extra charges they add for gold are a bit staggering.

Yep, some of the Detailed Parts Lists were created last summer. At the time, everything on the list was available. It seems that things have since changed.

One reason the Detailed Parts Lists are so, uhh, detailed, is to give builders additional information that helps when choosing substitutes. Physical size (shape of PCB footprint), tolerance, voltage rating, power rating, and so forth.

For example, Mouser has exactly zero 2.08K metal film resistors in stock. But they do have 4 different part numbers of 2.05K metal film resistors in stock, of the right physical size and wattage, and one of those four part numbers has twelve thousand pieces on the shelf today. (link)

 

[glenv6]

Yep, some of the Detailed Parts Lists were created last summer. At the time, everything on the list was available. It seems that things have since changed.

One reason the Detailed Parts Lists are so, uhh, detailed, is to give builders additional information that helps when choosing substitutes. Physical size (shape of PCB footprint), tolerance, voltage rating, power rating, and so forth.

For example, Mouser has exactly zero 2.08K metal film resistors in stock. But they do have 4 different part numbers of 2.05K metal film resistors in stock, of the right physical size and wattage, and one of those four part numbers has twelve thousand pieces on the shelf today. (link)

I have realized over the past year that rushing my order in for the parts any given vendor has in stock at that point in time is necessary to avoid the parts ordering treadmill. The treadmill starts the moment I save my cart to search for substitute parts, only to come back to my saved cart to find other parts suddenly out of stock. That has happened to me on parts showing availability of several hundred to several thousand over a matter of hours or overnight. I factor in 3-5x in shipping costs just for this reason. I’ve got get’em while you can syndrome real bad! 🤪

Having the details you have provided in such detail really helps when hunting for substitute parts - Thanks! 🍻

 

[rpafenberg]

I bought parts for the Missouri and the filter. Got U1 direct from TI, both for about $12. Between Mouser and a few parts from Digi key I was able to get everything I needed. Three or four were backordered but three of the four are due this month and the other the next. On a few of the parts, mostly registers, I just clicked on the important parameters of the backordered part that John was kind enough to provide and was able to find viable substitutes. I didn't try to find close register values because I didn't know what kind of tolerances we were dealing with. If the parts shortage continues, that is a parameter we might want to add to the BOM. I'm getting my boards from JLCPCB via the cheapest shipping possible. They will still get here before the last part. I still must order parts for the amp boards and the Nimitz.

Regards,

Roy

 

[mattattnet]

I hope this is not too off topic, but is this a correct 4 pin DIN chassis plug for the 36v Meanwell supply spec'd above?



Digikey 2092-KPJX-PM-4S-ND

Manufacturer Product Number KPJX-PM-4S


Or if not correct would anyone have a Mouser or Digikey part number for a correct chassis plug?

Thanks!

 

[Mark Johnson]

I have edited post #1 of this thread, to include Mouser.com part numbers for the rear panel DIN-4 connector used in the original VFET chassis. It mates with the recommended SMPS "brick" by Mean Well.

 

[mattattnet]

Thanks, Mr. Johnson!