On 6/29/2021 at 4:48 PM, starcat said:

Anyone tried the Dynalo Mk2 through-hole with Xicon 273 resistors? All the RN60Ds are 100ppm where the Xicon 273 are 50ppm, 1/2w... and cheaper as well.

I haven't built a dynalo with them but I built several cmoy 's back in the day just to explore resistor sound.  I used Vishay Dale RN60D, Holco H8, and Xicon.  Xicon came in last to my ear so I avoid them if I can.  I also use the IVY III output stage for my DAC and that uses Xicon resistors in it's stock form.  I switched them out for PRP and it was an improvement.  So I have two instances where I didn't like them in the signal path.  But feel free to try, YMMV and nothing ventured nothing gained etc. etc.

I'm reposting my parts list as someone requested it.  Probably needs to be double checked

Project_Nov08_0152PM.xls

Where can I find a schematic for the super symmetry version?

On 2/18/2022 at 9:48 PM, onewiththecrab said:

Where can I find a schematic for the super symmetry version?

kgdynalobalssproduction in the drive folder.

The link to that is in the thread

stax mafia circuit boards see updated links on page 5

Finished a set of v1.2 today. An excellent peace of gear! I'd like to thank Mirko and the contributors of the thread for their help (a very thourough source of information!!), dr. Gilmore and Spritzer for the design and instructions.

Full XLR, R38&R39 pots set to 250, w GRLV working on 20.1V (wo the final pot stage). Case, cooling and volume controll still pending.

Edited March 8, 20224 yr by JGergo
Clarification

Hi all,

• what is the latest non-SMD PCB Gerber file? I am looking at the google drive site and I cannot find "kgdynalobalssproduction".
• - Can someone suggest a case for the Kerry SMD version?
• what's the recommended  copper thickness for the Kerry SMD version? I'm seeing the posts that suggest it should be a minimum of 2oz 

Thanks in advance.

Hi again, what's the use of U5 and U7? seems redundant with U2 and U3 already there. Thanks

On 3/3/2021 at 3:00 AM, Bespav said:

Try here:
https://www.ebay.com/itm/Toshiba-2SJ74-2SK170-Quad-0-03-4-9-11-bl-B-/253517005056?_trksid=p2349624.m46890.l49292

can you please share the seller name? the link goes nowhere now. Thanks

punkydawgs is the seller. He has a current listing.

i need some help, i have a mini susy v1.5 tkd pcd, anybody have parts list or bom and the case? 

There are BOMs in the thread, but I've attached one here. There are alternate parts for some items, so check it over before you place an order. You can oftentimes save money by buying in quantity, particularly the SMD resistors (100 isn't unreasonable). The pricing in this isn't accurate as well.

Read thru the thread regarding cases (or search).

ssdynalo-v1-4.xlsx

thanks for the help. 

ssdynalo mini with 2sa1349 and 2sc3381 as input devices – on the small boards marked with red arrows.

 

On 2/24/2025 at 4:34 PM, JoaMat said:

ssdynalo mini with 2sa1349 and 2sc3381 as input devices – on the small boards marked with red arrows.

 

What is the favored method for affixing the heatsinks to the output transistors? After years on the shelf, I’m finally getting around to assembling this. 🤓

I used a 3M (Adafruit) thermally conductive adhesive tape. Mouser 485-1468 (80x80mm sheet).

53 minutes ago, Pars said:

I used a 3M (Adafruit) thermally conductive adhesive tape. Mouser 485-1468 (80x80mm sheet).

Thanks!

Before I start working topside, I have a question about the onboard regulator vs the AMB. I have both, and given the ability to get it attached, which is preferred? Is it better to just use the AMB and get the heat off the board?

 

I don't know that there is much difference between them, and since I've never been successful mounting the QFN packages, I don't know about any heat difference, but I would think the regulator contribution to this is swamped by the 32 PZTAs. If I could have mounted these successfully, that is the way I would have gone.

After building 4 of these, wishlist for changes/additions to the board would be:

1. Addition of Kevin's balanced protector circuit, with a manual mute switch.
2. Implementation of a delay circuit (5 seconds) for power application to the board to allow for the Meanwell bricks to come up at the same time. I determined that this was the source of the large DC offset I was seeing on the SE output when the amp is fired up. #1 above could take care of this if you made sure to mute the output for a couple of seconds while it is powering up.

These things do run hot. I have one of the ones I built for another user back for repair after it was left on with something on top of it. Amb notes on his forum when replying to a user who used his regs in a piece of Bryston equipment that they don't like heat very well. Since the LDO reg is really the only thing on his boards, this must mean that those reg chips don't like heat much. The GB boards were done using 3oz copper, making them about as good of a heatsink as you are going to get from a PCB (and a huge pain to work with). 

I had tried both then with the 3 oz board there was not much difference the onboard regs were a bit better. The big difference was to attach the transistor's heatsink to the box to drive the heat out. It may depend on what box you use that from the group by was good for this. I wrote about  it then

 

 

I had tried both then with the 3 oz board there was not much difference the onboard regs were a bit better. The big difference was to attach the transistor's heatsink to the box to drive the heat out. It may depend on what box you use that from the group by was good for this. I wrote about  it then

The little amp is at my bed sometimes I forget to switch it off. There was not problem with it for about five years(?).

 

I’ve got the group buy case…planning on adding the 5mm aluminum bar to it.

3 hours ago, judo said:

I had tried both then with the 3 oz board there was not much difference the onboard regs were a bit better. The big difference was to attach the transistor's heatsink to the box to drive the heat out. It may depend on what box you use that from the group by was good for this. I wrote about  it then

The little amp is at my bed sometimes I forget to switch it off. There was not problem with it for about five years(?).

 

Thanks Pars! I’ll need to think some more about the regulators while I wait for some MMBTA06 to come in I didn’t realize I never received… What LED and bias resistors did you end up with in the end? I’ll put mine in the sheet once it’s up and running. Likely will use 402 / 240 with the LTST-C170CKT. 

8 hours ago, Pars said:

I don't know that there is much difference between them, and since I've never been successful mounting the QFN packages, I don't know about any heat difference, but I would think the regulator contribution to this is swamped by the 32 PZTAs. If I could have mounted these successfully, that is the way I would have gone.

After building 4 of these, wishlist for changes/additions to the board would be:

1. Addition of Kevin's balanced protector circuit, with a manual mute switch.
2. Implementation of a delay circuit (5 seconds) for power application to the board to allow for the Meanwell bricks to come up at the same time. I determined that this was the source of the large DC offset I was seeing on the SE output when the amp is fired up. #1 above could take care of this if you made sure to mute the output for a couple of seconds while it is powering up.

These things do run hot. I have one of the ones I built for another user back for repair after it was left on with something on top of it. Amb notes on his forum when replying to a user who used his regs in a piece of Bryston equipment that they don't like heat very well. Since the LDO reg is really the only thing on his boards, this must mean that those reg chips don't like heat much. The GB boards were done using 3oz copper, making them about as good of a heatsink as you are going to get from a PCB (and a huge pain to work with). 

 

Edited January 3Jan 3 by GrindingThud

I'm pretty sure I just used the Lite-On LTST-C170CKT LEDs and the 402R resistors. 

It’s alive! Getting the offsets adjusted is so touchy…finally got it below 2mv as it drifted about. Did it without heatsinks after being on for a while. It seems to settle in around 14ma with the LTST-C170CKT LEDs and the 402R. Running 240R vice the 255R. Will likely let this cook for a while and see if it needs any tweaks. That front panel light is a bit bright…may need to tone that down a bit… 🤓

Edited January 9Jan 9 by GrindingThud
Added led comment

Update after listening all day with it closed up - temps in the base of the heatsinks are at least 77°C, current is 14.2 mA. Yep, it’s hot. The batteries crapped out in my IR thermometer, so I used a high end contact meat thermometer between the fins, lol 🥩. The heat sinks are not in contact with the case…I may try the aluminum bar mod if it gets too hot. 

21 hours ago, GrindingThud said:

Congrats!

21 hours ago, GrindingThud said:

That front panel light is a bit bright…may need to tone that down a bit… 🤓

I have changed it too and now I can not see it in daylight so I  plan to change it again for a couple of years  😞

 

 

Edited January 9Jan 9 by judo