TomWaterman
Well-known member
Been in more contact with Sowter and have determined some more info you might be interested in.
They chased up the trafo numbers Peter Purpose provided in an earlier post:
Type 3955 is 600/600 line output transformer.
Turns ratio is 1:1.06. Frequency response +or- 0.5dB 20Hz-
30kHz, Max level = 10V rms at 30Hz. with electostatic screens.
Clamp mounting, size is 51high x 60.5 x 36mm across the coil,
with fixing centres at 73mm (size k style A).
Type 3777 is modified 2318
same turns, same specification but wound on a split bobbin for
best possible balance.
Price for 3955 is £52.22 (this is much more expensive than 8403
because it is larger, uses a Nickel core and more winding sections).
Price for 3777 is £48.75 (more expensive than 2318 due to the
more complex winding require on the split bobbin).
So we now have a line on original output iron if you want it or any other suitable 600:600...(maybe Cinemag have something cheaper and more readily available for you US guys?)
This info also provides two input transformer choices - the slightly cheaper 2318 at 46GBP-ish or the 3777 which is a slightly better version at sightly more cost....these are not cheap pieces of iron but their cost will drop if we do a decent group buy...
Anyway I have a question as I want to order a single set this week to prototype the new preamp layout etc. I'm going for the 3777 as it seems the best choice for input tx, however I'm uncertain about the added cost and size of the original output tx. The sowter package guide lists it as 40mm high, thats not going to fit in a 1U rack is it? Thats what I require but can't find any internal dimensions for a 1U chassis..
I would love to have original spec iron for this but am worried about the fit - am I better off going with Sowters own 8403 which is considerably smaller and has a diff. core material?
To ask the impossible I don't know much about transformers but understand that Nickel (Nickle (SP?)) cores are cleaner than steel...would perhaps a 50/50 Cinemag CMOB-2/3L be a viable alternative? Its quite a bit smaller and would offer a different tone with maybe more colour I guess?
Was doing a layout with PCB mounted TX's but Sowter cannot do the input TX in a smaller can that will fit in 1U without sourcing an 'L' mounting bracket so I have decided to leave the transformers of the board. This way you can add whatever you want.
Anyway I thought some of this might be interesting to some of you. I could use some advice on the Sowter transformers anyhoo...
Cheers Tom
They chased up the trafo numbers Peter Purpose provided in an earlier post:
Type 3955 is 600/600 line output transformer.
Turns ratio is 1:1.06. Frequency response +or- 0.5dB 20Hz-
30kHz, Max level = 10V rms at 30Hz. with electostatic screens.
Clamp mounting, size is 51high x 60.5 x 36mm across the coil,
with fixing centres at 73mm (size k style A).
Type 3777 is modified 2318
same turns, same specification but wound on a split bobbin for
best possible balance.
Price for 3955 is £52.22 (this is much more expensive than 8403
because it is larger, uses a Nickel core and more winding sections).
Price for 3777 is £48.75 (more expensive than 2318 due to the
more complex winding require on the split bobbin).
So we now have a line on original output iron if you want it or any other suitable 600:600...(maybe Cinemag have something cheaper and more readily available for you US guys?)
This info also provides two input transformer choices - the slightly cheaper 2318 at 46GBP-ish or the 3777 which is a slightly better version at sightly more cost....these are not cheap pieces of iron but their cost will drop if we do a decent group buy...
Anyway I have a question as I want to order a single set this week to prototype the new preamp layout etc. I'm going for the 3777 as it seems the best choice for input tx, however I'm uncertain about the added cost and size of the original output tx. The sowter package guide lists it as 40mm high, thats not going to fit in a 1U rack is it? Thats what I require but can't find any internal dimensions for a 1U chassis..
I would love to have original spec iron for this but am worried about the fit - am I better off going with Sowters own 8403 which is considerably smaller and has a diff. core material?
To ask the impossible I don't know much about transformers but understand that Nickel (Nickle (SP?)) cores are cleaner than steel...would perhaps a 50/50 Cinemag CMOB-2/3L be a viable alternative? Its quite a bit smaller and would offer a different tone with maybe more colour I guess?
Was doing a layout with PCB mounted TX's but Sowter cannot do the input TX in a smaller can that will fit in 1U without sourcing an 'L' mounting bracket so I have decided to leave the transformers of the board. This way you can add whatever you want.
Anyway I thought some of this might be interesting to some of you. I could use some advice on the Sowter transformers anyhoo...
Cheers Tom
