Can anybody tell me what´s the difference in sound between the Urei 1176 and 1178?(I know, the 1178 is stereo) I think there are only silverface 1178 around. Is there an difference like with the 1176 blackface/silverface? Is there something in serial-numbers that´s important? Is the four- Buttons-In-Trick working with the 1178.
Hope somebody can help me.
An 1178 is not a dual 1176.
The older 1176 is made up of transistor and two FETs. The later ones did go to an op-amp input and changed the output amplifier. They is an op-amp to drive the gain reduction meter. The detector circuit is pretty much the same for all models oof 1176 BUT the transistor did change and there are slight circuit cahnges to go with them. There were also slight changes with the power supply.
The 1178 was a shorter live unit. It is all op-amp and not the same as a 1176 at all. Very different detector section and uses a dual FET package instead of two single FETs.
I rushed all that a bit so it doesn't tell the whole story but I hope you get the drift.
If you are interested, drop me an email , I have many circuits for both and I am in the process of making a 1176. The 1178 is a project for the future.
I think we had an extensive thread somewhere on RO covering this topic. Check the search function.