Rooford
New Head-Fier
- Joined
- May 20, 2009
- Posts
- 44
- Likes
- 10
Hi,
Completed my SOHAII build over the weekend after a few errors (E12 regulators were reversed) it sounds great. Kudos to Alex for the design and making it available to the DIY community.
However, with sensitive earphones (Etymotic) I did get a constant amount of hum despite trying different ground methods. Volume control didn't make any difference to the loudness of it.
Rotating the transformer worked wonders here, I'd consigned myself to moving the transformer out of the case.
To complete it I need to find a suitable top and source some isolation washers for the input jacks.
As the amp runs pretty hot I was thinking of using a perforated top, I found something that might work on Ebay here:
3003 Hex Perforated Aluminum Sheet .032" x 12" x 48" - eBay (item 350270376416 end time Mar-25-10 12:21:42 PDT)
As the holes are pretty big there's potential for dust build up which I know can be a problem for very high voltages (arcing) although I'm not sure if this applies to the soha.
While this gives 79% open area there's also a sheet perforated alu at 40% open area.
Does anyone have an opinion on which would be more suitable, I'm erring on using the 79% to keep things as cool as possible?
For isolation washers I'll try my local hardware store but I anyone has any other suggestions that would be appreciated too.
Completed my SOHAII build over the weekend after a few errors (E12 regulators were reversed) it sounds great. Kudos to Alex for the design and making it available to the DIY community.
However, with sensitive earphones (Etymotic) I did get a constant amount of hum despite trying different ground methods. Volume control didn't make any difference to the loudness of it.
Rotating the transformer worked wonders here, I'd consigned myself to moving the transformer out of the case.
To complete it I need to find a suitable top and source some isolation washers for the input jacks.
As the amp runs pretty hot I was thinking of using a perforated top, I found something that might work on Ebay here:
3003 Hex Perforated Aluminum Sheet .032" x 12" x 48" - eBay (item 350270376416 end time Mar-25-10 12:21:42 PDT)
As the holes are pretty big there's potential for dust build up which I know can be a problem for very high voltages (arcing) although I'm not sure if this applies to the soha.
While this gives 79% open area there's also a sheet perforated alu at 40% open area.
Does anyone have an opinion on which would be more suitable, I'm erring on using the 79% to keep things as cool as possible?
For isolation washers I'll try my local hardware store but I anyone has any other suggestions that would be appreciated too.