Sumthang guts

[ruffrecords]

Has anyone ever taken the lid of a Sumthang to see what is in it? seems to be a bit of a mystery tube device.

Cheers

ian

 

[pucho812]

This is a guess, passive summing with tube make up stage. The make up stage has metering and one stereo pot for control.  It also appears to have input transformers, output transformers, and be wired point to point... Mind you all a guess and I have never worked into one. Here is a quote from their website.

Wired in Point to Point, its Eight Custom input Transformers feed Super Stayne Rocket fueled Tube amplifiers that have the capability to send your ears into outer space....

 

[ruffrecords]

Yes, I have read their sales blurb too but I wonder if it is as simple as that. I cannot see the point of the input transformers unless you have a tube stage per channel and THEN do the summing. If it were just a passive summer with tube gain make up then there would be no need for the input transformers. That's one reason why I wanted to have a look inside. Surely someone somewhere has access to one they can take the lid of and take a pic?


Cheers

Ian

 

[okgb]

Besides the marketing mojo of using transformers [ they're just like tubes right ? part of the magic!]
they are useful for unbalancing & isolation , [ easier than keeping a balanced tube circuit? ]
I would guess they are 1:1  but for the added cost I wouldn't think they're added only for hype.

 

[pucho812]

What if the transformers were  more then just 1:1ratios say step down transformers

 

[gyraf]

Do we know if it's really tube-only?

A cheap way of implementing input transformers is to use them in zero-field configuration, but requires at least an opamp per trafo...

Jakob E.

 

[gridcurrent]

I would guess they are 1:1  but for the added cost I wouldn't think they're added only for hype.

The input transformers are fairly high ratio step-down.

 

[gyraf]

Do we know that?

 

[okgb]

Also assuming it's line level, the ratio if not 1:1 would not be too extreme anyway
what's the homemade looking image of?

 

[pucho812]

The input Ω per channel is 25KΩ, output Ω is designed to be loaded 600Ω and is transformer as well.

The unit is completely passive with tube make up stage. I confirmed that with someone who has access to one The make up stage is octal tubes 12sn7 and 12sl7 This is the same amp stage used in other innertube audio equipment.

 

[velo]

Has anyone ever taken the lid of a Sumthang to see what is in it? seems to be a bit of a mystery tube device.

Cheers

ian

I may have a precursor or something similar (or not) from Stayne - an unmarked box with a large knob. But really I have no idea what this is. After opening it now I have a bigger problem. Not a mixer. I knew that. I guess this is off topic.