[13mh13]

Having owned a few AVA-upgraded Magnavox units, I know they are capable of v. good sonics! Still have a CDB-582!
I generally prefer the classic multi-bit sound to delta-sigma, so I'm always on the lookout for AVA d/a's in the used market.
However, because many of the classic used-market AVA dacs are several decades old, it is difficult to tell whether these AVA's are truly original -- that is, whether they have not been further modified by another party, or whether good stuff has been extracted (or cheaper parts substituted)  prior to the eBay or Craig's List placement.

To that end, much appreciated if:  Frank, or anyone in the audience, more familiar with older AVA dacs, can please clarify what dac chip(s) and/or digital filters (as in a dual chipset) were used in:

The Omega III TOPP-DAC   solid-state DAC. (1997)

The Fet Valve TOPP-DAC (1997)

ULtra DAC (2006)

OmegaStar DAC  (2006)

AVA Audio by Van Alstine Transcendence Eight T8 Phillips TDA1543 6922 Tube DAC
listed here:
 https://www.usaudiomart.com/details/649563684-ava-audio-by-van-alstine-transcendence-eight-t8-phillips-tda1543-6922-tube-dac/

[jjss49]

my old thread will help you

https://www.audiocircle.com/index.php?topic=172726.msg1826521#msg1826521

[ArthurDent]

I'll take a look at my Ultra DAC, see if I can tell what's what. I know I upgraded the chips in my Insight DAC, and an amp around '08 with I believe the Burr-Brown ones he changed to for the Insight+ series. Should still have the original Insight chips here somewhere too.

[13mh13]

my old thread will help you

https://www.audiocircle.com/index.php?topic=172726.msg1826521#msg1826521

Unfortunately, neither the photos nor the discussion in that thread reveal the central topology. Like the DAC chip, DF chip, I/V and output circuitry.
That said, the premium parts and build quality in the photos are typical AVA. A good home-cooked meal.

[ArthurDent]

For info [Correction]  the upgrade chips were to my Insight DAC, Not the Ultra. The Ultra DAC originals are the Burr-Brown OPA627APs. Still looking for the original chips. My unit was built in Sept of 07, As to the other chips: there's (1) Phillips TDA1543, a Texas Instruments 69CM02M & 65K11RK, what may be another TI XM05AD VIP, and a Cirrus Logic CS8412CP. All these are on the main board. There's one more at the back on a small board near the connections, a TI 66FER9K. Hope this helps.

Now I need to swap the 6N1P tubes for the upgrade 6922 units and blow the dust off. I've already made that swap in my old Ultra Pre-amp to do a comparison of the phono units between it & my gen 1 FET Valve CF pre. So far prefer the old tube phono to the newer SS unit. Will let you know when I find the original Ultra chips.

Apologies for my confusion, getting old & drifty.

[13mh13]

For info the upgrade chips in my Ultra DAC are the Burr-Brown OPA627APs. Still looking for the original chips. My unit was built in Sept of 07, I got the new chips from Frank in '08 simple swap. As to the other chips: there's (1) Phillips TDA1543, a Texas Instruments 69CM02M & 65K11RK, what may be another TI XM05AD VIP, and a Cirrus Logic CS8412CP. All these are on the main board. There's one more at the back on a small board near the connections, a TI 66FER9K. Hope this helps.

Now I need to swap the 6N1P tubes for the upgrade 6922 units and blow the dust off. I've already made that swap in my old Ultra Pre-amp to do a comparison of the phono units between it & my gen 1 FET Valve CF pre. So far prefer the old tube phono to the newer SS unit. Will let you know when I find the original Ultra chips.

Excellent info! But I have no idea what: "a Texas Instruments 69CM02M & 65K11RK, what may be another TI XM05AD VIP" are ??? Maybe FPGA's doing oversampling?
A possible mod (with different sonics) is to swap that 1543 with a tda1387. I have done so on a 1989 Magnavox CD2000. Not better, just different.

Nota bene:
Pictures can also help as they indicate layout, topology, build quality and quality of components (e.g., HQ Vishay resistors and Matsushita poly caps are typical AVA).
Yes, with images and schematics and over-description, there is the perceived threat of copyright infringement, and low-cost Chinese duplication. But, I don't think AVA really has these competitives to worry about. That home-cooked meal is difficult and cost-prohibitive to market on an economies-of-scale basis.
The AVA community is small, and long-term enough (me, since 1984!!), and clientele-populated enough, to support FVA, ad infinitum,  because we want the reassurance comfort-factor of having the Real McCoy communicating music, after a long day at the office.

[jandrews]

Does anyone know the chip used in the Transcendence R-Dac”?

[ArthurDent]

Excellent info! But I have no idea what: "a Texas Instruments 69CM02M & 65K11RK, what may be another TI XM05AD VIP" are ??? Maybe FPGA's doing oversampling?
A possible mod (with different sonics) is to swap that 1543 with a tda1387. I have done so on a 1989 Magnavox CD2000. Not better, just different.

Sorry, not a EE, or even an audiophile in the sense of most here, just an enthusiast who likes music. Your question was what chips were original in the noted AVA DACs, that's the info provided for my Ultra. As to exactly what they do and how they do it you'll have to talk to Frank, or someone more knowledgeable than myself.

[13mh13]

I do believe that way back in the early 90s, FVA noted some shortcomings of 1-bit DACs, which are essentially "Delta-Sigma".  D-S has since evolved and maybe improved , but does have a certain sound characteristic.
Since multi-bit DACs (Schiit, Denafrips ,etc) seems to have gained some resurgence, AVA could potentially re-enter that market (and not remain in mainstream Delta-Sigma AKM, TI Cirrus, Wolfson or ESS).
Also, given that AVA does not sell in huge volumes as, do Schiit, et al., there are still low-cost (new-old-stock) sources for popular Philips chips. For example, I routinely look for deals on Ali for tda1543s, tda1387, etc.