AMB Laboratories DIY Audio

[amb]

AMB audio shop has taken over the distribution of dynahi PCBs from Dan Gardner.
(UPDATE: Dynahi amp PCBs are sold out, but some parts are still in stock).

dynahi Reference
- Headwize dynahi thread
- Headwize dynahi PSU thread
- Dan Gardner's Gilmore amp reference site

Notes
- The Toshiba 2SK389 and 2SJ109 dual-JFETs are obsolete. Substitute with matched 2SK170BL and 2SJ74BL quad (available from AMB audio shop).
- The Toshiba 2SC3381 and 2SA1349 dual-BJTs are obsolete. Substitute with matched pairs of 2SC2240BL and 2SA970BL (check B&D Enterprises).
- The Toshiba 2SC3421Y and 2SA1358Y output transistors are no longer available from AMB audio shop (check B&D Enterprises).
- Instead of the specified OP27 opamp for the DC servo, I recommend using OPA134PA or OPA132PA for better performance.
- The σ22 (configured for ±30V output) is the recommended high-performance power supply for the dynahi.
- A limited quantity of Gilmore-designed dynahi PSU boards are also available.

Related projects
- The σ22 regulated power supply

[mattcalf]

Awesome work for the DIY community, thank you Ti!

[K3cT]

Congratz, this is awesome!

[housing]

Is the board the same as Dan supplied before? I have a stereo set of Dynahi built and would like to convert it to balanced output by building 2 additional channels.

[mattcalf]

I believe the boards were passed on from Dan, so you should be alright.

[amb]

Yes, they are identical.

[vixr]

amb, you recommend the σ22 PSU for the dynahi, I have the original dynahi PSU board from the GB a few years ago...I would kinda like to keep the overall dynahi theme going by using the PSU board. Do you have any tweaks for the dynahi PSU? Could you explain a bit about why you recommend the σ22?

EDIT: OK, I got off my butt and read the dynahi PSU thread over at headwize...compared it with the σ22.

[amb]

amb, you recommend the σ22 PSU for the dynahi, I have the original dynahi PSU board from the GB a few years ago...I would kinda like to keep the overall dynahi theme going by using the PSU board. Do you have any tweaks for the dynahi PSU? Could you explain a bit about why you recommend the σ22?

EDIT: OK, I got off my butt and read the dynahi PSU thread over at headwize...compared it with the σ22.

Nothing wrong with the dynahi PSU except it's $$$ if you blow out the OPA541 power opamps -- keep it if it's working well. For new builds, σ22 costs less, is easier to build and has slightly better performance. Use the dynahi PSU if you are a purist and want to keep the whole amp "Gilmore designed". Even KG himself now recommends using σ22.

[vixr]

I have unpopulated amp and PSU boards...I would like to try to keep it all KG but I dont want to be stupid about it either. Purism has its merits, but I intend to keep the amp for a long time...perhaps the σ22 would be best. Thank you amb for setting me straight.

[digger945]

Do you listen to your Dynahi much Ti?