Comments on: Altec 438A – Modified for modern music production use

By: Eric

Eric — Sat, 27 Jul 2024 13:03:44 +0000

Do you have a schematic with the changes you’ve made? Am curious how to expand compression ratio to this circuit. Thanks.

By: Joshua

Joshua — Thu, 26 Oct 2023 17:49:55 +0000

But to clarify, this is at mic level or line level post mods? I think this is what differentiates the 436 from the 438 as this was used as a preamp for public address. Is that correct?

By: karel

karel — Tue, 17 Oct 2017 21:08:47 +0000

In reply to chris. thanks

By: chris

chris — Sun, 24 Sep 2017 16:15:14 +0000

In reply to karel.

“Line” injects signal directly to primary of transformer #2, bypassing transfo 1 and gain stage 1/2

By: karel

karel — Sun, 24 Sep 2017 15:16:43 +0000

hello , can you explain the modification for the mic / line switch ?
Is this a simple PAD, and is the line signal still going thru the input transformer ? thanks

By: Don Bell

Don Bell — Wed, 04 Nov 2015 02:21:31 +0000

You can also modify the attack by putting in a switch to select a cap about half the value (.5 ufd) instead of the stock Altec (1.0 ufd). This gives you a faster attack time.