Ok, so a little story on transformers. When bringing the SA-2A to life I had seven prototypes made by Cinemag until we found the specs and models we liked the most which were very close sounding to the originals. After a year and on the constant search of improving my units I sent two SA-2A's to reputed producer Greg Wells (I am sure everybody knows who he is) and to Bill Jones from Kenettek who is one of the engineers I most respect and admire for his work.
After running some tests Bill concluded that the Sowter's made a significant improvement and that they sounded much closer to a Vintage LA-2A, I was also told by Drip Electronics that the Sowters were identical to the UTC's a long time ago. The input transformer made the larger difference while the output made a slight improvement. All of this improvements were recorded and measured to make sure they were real.
I then sent both compressors to Greg, who has 50k speakers, a bunch of vintage compressors and overall golden ears to see if he could hear what the specs said on papper. One of the SA-2A's had the Cinemags and the other Sowters, I did not tell him which had which. Greg came back to me and kept one, he said both sounded good but one was more 3D sounding and had quickly become his favorite compressor among so many vintage and expensive units, the one with the Sowters.
The new SA/2A comes with a Sowter input transformer and a Cinemag output, this is the only way to maintain the same price but improve on the existing product, adding a Sowter output would push the price to 990 on pre/orders and 1.090 in stock. I also added NOS carbon resistors on the audio path on the new SA2A for a more vintage tone. The toroidal transformer has also been upgraded.
So, long story short, I recommend moding the SA2A and replacing the input transformer, C9 must be replaced by a 270pf cap.
This will make a far great difference than tubes. I am now using Sowter transformers in almost all products (SA87, 1176, 1073 and 312). They are more expensive and my margins have decreased but sound comes before money too me.
I have never heard the WA-2A and it is not my place to say which one sounds the best even if I had, all I can say is that the new SA-2A sounds superior to the previous SA-2A which already sounded extremely good to me, so I am happy!.
I will upload some documments to the website soon with all the information required to upgrade your units. The Sowter 1449f can be purchased from
www.sowter.co.uk, the wiring and details will be uploaded to their website as well.
Thanks!