Recent content by oldphaser

These were made by Dan Kiefer when he worked at Phase Linear in the engineering/prototype department. These were never intended to be put in production and a handful were made in order to satisfy each one of the co-workers that he had to involve in getting them made. Whenever Dan made some of...

Don, I am sorry for the slow reply. I've been out of town for about 2 weeks taking care of my older brother. Indeed 400 and 700 transformers rarely ever failed. If my memory serves me correct, Dean has only seen (1) failure between the 400 and 700 series amps. Likewise for me. On the other...

Don, I just went through one of my many Phase Linear 3-ring binders... I found a Phase Linear "item price list" dated 8/13/82 (102 pages). It lists the item number, item description, net price, and retail price. Likewise, I found a 48 page "Service Department Parts Listing" dated 1/16/84...

I thought I had remembered a post about Greg Johnston winding transformers. Sure enough, here is a post by Robin Gudgel (former Phase Linear employee).: https://midniteftp.com/forum/index.php?topic=474.30 "In my early days of audio, 1971, at Phase Linear, Steve Johnston was Bob Carver's...

In these situations, it also helps that I have a copy of the 86 page Phase Linear Master Parts Catalog dated 4-8-1981. The X-formers are listed on pages 84-86. I obtained the list from the estate of Dan K. after he passed away. Dean was going to throw it in the garbage. I only wish I had a more...

Early Phase Linear 700's (sometimes referred to as a 700 series 1) transformers were made by Bob Carvers brother Chuck. According to Bob Carver, these transformers can be identified by the color of the shellac on the windings. Unfortunately, I can't recall what the colors were. Some of the...

David Willard (the draftsman at Phase Linear) used to like sneaking in things like "Fudder Mudder" on circuit boards. Management wasn't too happy about this. Mike F. was Mike Frost. Mike worked in the engineering department at Phase Linear. Unfortunately, Mike passed away in 2016.

It has been a while since I last worked on a 3300. However, I seem to recall running into problems with at least one headphone jack before. "The SW outputs are turned off when a headphone is plugged in. This allows headphone listening without speaker background sound. The UNSW outputs are not...

Here is a little more history on the Triad Transformer Mfg. Company now Triad Magnetics. "Talking With Triad Magnetics: Demystifying the Science Behind Audio Transformers" by Frank Doris in PS Audio Copper magazine March 25, 2025 Issue 216...

Here is a link to my recent post on the Triad G-336 transformer: https://forums.phxaudiotape.com/threads/phase-linear-bridging-information-using-triad-g-336-transformer.12173/

Here is a link to my recent post on the Triad G-336 transformer: https://forums.phxaudiotape.com/threads/phase-linear-bridging-information-using-triad-g-336-transformer.12173/

I have gathered up some historical information concerning the Triad G-336 transformer. There were several Phase Linear service bulletins issued (one has been previously posted on this forum) as well as a couple Triad documents. Also included is a photo of a G-336 transformer I acquired a...

I don't know what the original intent for the Cerwin Vega A-2800 was. I am curious what the B+ and B- voltage rails were and if the amp was a bridge amp.

Ron, Here are some pictures of an Cerwin Vega A-2800 mono-block power amplifier I found on the internet. The amplifier used a total of (16) GM/Delco DTS-411 transistors. NOTE: Many are already aware that the GM/Delco DTS-411 transistors were also used by Phase Linear (in their 400's and 700...

The AI-sphere can't be trusted. The copy of the RCA410 datasheet from 11/1973 like the one you posted is the earliest one I can find so far in all the documents I have gone through. "Simultaneous and nearly independent developments by GM's Delco Radio division and Motorola led to the widely...