JCF DA8-V or Ampex 351 Repro Electronics DIY

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Well-known member
Nov 29, 2014
Hi, I've recently learned about the JCF DA8-V digital to analog converters that have a Ampex 351 repro electronics style, tube output stage and I'm very intrigued by the idea of a less than transparent, tube sounding digital to analog conversion that feeds my summing mixer. At the price of $9500 per 8 channels, it's got me thinking if there is potentially a DIY option to pair with my current converters. Something like 8 channels of tube line amps that would offer a similar type of color before going into my summing mixer. The conversion quality of my Symphony converters still may not be quite as good as the JCF, but if I could at least mimic the tube electronics stage of the DA8-V, I would be happy. Does anyone know of something like this? I'm particularly interested in Ampex or RCA style tube circuits.

Here is a link to JCF converter for those of you who aren't familiar JCF AUDIO
I dumped an earlier draft/reply on this topic because my comments were blabbing about my life-long tech support and user experiences (mostly GOOD) about Ampex machines.

Nitty Gritty! Maybe 20 years ago, I had a 351 audio electronics chassis (AKA "Phat Ampex 351 mic preamp") for repairs. The output transformer had an open in one half of the primary winding.

At that time, the Ampex users email list folks mentioned the 9084 Sowter as a replacement. Sowter still lists it.

Egads! Nowadays close to 100 Pounds Sterling......far more than it used to be.

Cinemag doesn't have online pricing, but they always have reasonable pricing. You can find tech info re. the 9600-T on their website.

In this design situation, you have to ponder the LARGE number of 12AX7 and 12AU7 bottles with one each required per channel; eight channels would be eight of EACH firebottle.....sixteen total. egads!!!! lol

Then add eight chunky output transformers. I saw somewhere on the JCF website the shipping weight for a system was around 60 pounds including power supplies.

I'm certainly not down playing the concept.....just pointing out what a huge gizmo eight channels would be! I'm also a bit leery of how much stuff JCF has stuffed into a relatively small package.