Sparkos Labs BA312-M modules,

KutzlerTrans

Jennie & I with Buddy and Barney.
So whats up with these git-ups.
Any opinions of them and is the cost worth what you are hearing.
I may just stuff a set into the shop 2325 if it is indeed a better upgrade.
Thanks for your feedback.
 
I installed mine about two weeks ago and have enjoyed them thus far.

The biggest improvements noted: an additional 10dB of gain in the phono stage, cleaner sound overall than before and a considerably lower noise floor; dead quiet; no more grainy sounding backgrounds.
I'm loving that because I'm using my 2325 for playing vinyl records almost exclusively.

To be fair though, I run a separate phono pre-amp and just recapped P800 board, so that is something to consider overall as well.

My experience with Andrew from Sparkos Labs was positive.
Andrew treated me right, was excellent with his communication, was prompt with shipping and the product was packaged professionally.

Here's a few pics of PE01 with the new modules and components....
The main thing with this project was getting all of the caps on PE01 to fit like a jigsaw puzzle. I had to really bend component leads in what seemed like extreme ways in order for all of them to fit, but it turned out great and I'm happy with the sound!

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Echo,
I'm confused as to how a modification to the tone-preamp board (PE01) can affect the gain of the separate phono preamp (P400)?

Tom
 
Prior to doing the rebuild, I had the gain setting on my separate phono pre @ 50dB. That’s just where it sounded the best to me. But, after installing the new modules and other components, that setting was way too loud.

Then, I lowered the gain level to 40dB, and found the sweet spot. Here’s where it gets interesting...I’m getting the same volume output @ 40dB with the new components and quieter background levels. Whereas before, it was 50dB on the old components. The lower noise floor improvement in phono mode has been awesome!

I hope that helps answer your question a little Tom. Sorry, I don’t mean to ramble here. Just wanted you to know what I’ve experienced thus far.

I think it would be wise of Andrew to get these modules in your hands and Leestereos so you can both test drive them and measure the results. I don’t have the equipment or the circuit knowledge that you two have, but I’d like to hear your test results on them.

I know right now, my ears are happy. I don’t want to oversell these as being the be-all-end-all, but in terms of noise and output there has been a noticeable difference and improvement made.
 
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I installed Andrew's discrete op amps in place of the LM301AN op amps in my Marantz 3800 and I must say it opened up the extreme ends of the audio spectrum and has a more "transparent" sound stage. I have been listening to the arrangement for a few months and still I am amazed at the difference from the factory op amps. The next step would be to talk to Andrew about replacing the F749PC with his dual channel discrete op amp.

PS I also have the BA312 replacements waiting to be installed in my 2275 but haven't done so yet as I am using the 3800 as a pre for the 2275 and just enjoy this arrangement, besides the weather is way too nice to be sitting at the bench :<)
 
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Update...

I just emailed Andrew regarding the gain output on the Op Amps and he confirmed that there is a slightly higher gain output and that it will vary depending on the model it's used in. Meaning on some Marantz models, the gain will be either lower or higher. He didn’t specify which models they are. On my 2325, the gain is definitely higher than it was originally, which explains why I had to lower the output gain setting on my phono preamp back to 40dB.

I’m going to try and find the technical datasheet I read on-line for the BA312-M modules. I believe the fella that was originally involved in developing the BA312-M had more technical specifics than what Andrew currently has posted on his website.

I’ll report back when I find out more...
 
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Here ya go...
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IMCO (in my crappy opinion), it's an expensive solution in search of a problem.
Am I reading that last graph correctly, in that the measured differences are in tenths or 1/100ths of dB? Two different unmodified units could show as great or greater differences.
 
Tarior,

In my case, the audio hobbyist in me likes to experiment around with different components...just kind of fun to see what works and what doesn’t... and how it effects the sound quality overall.

If I had proper testing equipment other than a soldering station and multimeter I’d be happy to post measurements and discuss, but alas, I do not so my ears have to be my guide; subjective to say the least. That being said, I’m not necessarily advocating folks go out and change their units with this mod. I have to admit, its been more fun than practical...in my case anyway.

For me, I just thoroughly enjoy this hobby, getting to learn more about it and meeting and sharing with folks here on AK.
 
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I am currently in the process in restoring and upgrading my Marantz 2285. On AK I've come across SparkoLabs module to replace the dated BA312 IC. From previous experimentation I've found the Burr-Brown OPA627 to be the best sounding IC for audio purposes. Has anyone tried the adapter from Vintage Audio Adapters (with the same pin configuration as TA 7136) where you can use any 8-pin IC of your choice. This option is also less expensive (the adapter costs $9.99 on eBay). I'm inclined to go this route but first I would like to hear from anyone who has tried and compared these two options.

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So whats up with these git-ups.
Any opinions of them and is the cost worth what you are hearing.
I may just stuff a set into the shop 2325 if it is indeed a better upgrade.
Thanks for your feedback.
I installed a set on my 2285 several months ago and I agree with Echoplex. It is a definite improvement.
 
I installed a set on my 2285 several months ago and I agree with Echoplex. It is a definite improvement.
I've really got to get er done but I use my 2325 all day every day and I just hate the idea of being without it. When I do it it's going to be a complete teardown because I have other issues to deal with icluding power switch and snubber, redoing velum and a noisy speaker selector (the hardest switches to get to).
 
I'm about to install the Sparkos modules on my 2285 (not B) along with a major overhaul where transistors and caps are to be replaced, caps with polypropylene when possible in the signal path. I want to unlock the potential the modules have by not masking their performance with old elyt caps/unnecessary elyt caps in the signal path. With the module kit comes two 10uF Nichicon Audio caps to replace current 3.3uF stock caps in locations CE13 and CE14. I understand from Andrew that the purpose for the increase is to address a bump that BA312 has in the lower region. When I'm looking at the schematic I see that the following output stage has a 1uF cap in front of that stage (CE33,CE34) acting in a low-pass configuration. So if the purpose of CE13/CE14 is for DC-blocking rather than correcting low end frequency response (when using the modules) wouldn't this cap be redundant since we have a dc-blocking cap (CE33,CE34) right after in the signal path? By replacing CE13/CE14 with a straight wire I get one elyt cap less in the signal path and more room for the large polypropylene caps.. Has anyone tried this and what was the result?
 
I installed Andrew's discrete op amps in place of the LM301AN op amps in my Marantz 3800 and I must say it opened up the extreme ends of the audio spectrum and has a more "transparent" sound stage. I have been listening to the arrangement for a few months and still I am amazed at the difference from the factory op amps. The next step would be to talk to Andrew about replacing the F749PC with his dual channel discrete op amp.

PS I also have the BA312 replacements waiting to be installed in my 2275 but haven't done so yet as I am using the 3800 as a pre for the 2275 and just enjoy this arrangement, besides the weather is way too nice to be sitting at the bench :<)

I blowed up my 2275 BA312 so I had no choice but to install the BA312M upgrade. Instructions were easy, parts were complete and it fired up the first time and sounds great. Performance numbers are a vast improvement.
 
I've seen those numbers before, and they are a very long way from being a dramatic improvement. People believe what they want to believe.
 
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I've seen those numbers before, and they are a very long way from being a dramatic improvement. People believe what they want to believe.

Well, I have to disagree, the publicized numbers are definitely a dramatic improvement. The question seems to be, do I believe the numbers? My answer is no. Typical testing bullshit, playing with the testing to inflate numbers.

2275 original THD .25%
McIntosh MC611 (new) THD .005%
BA312-M .0073%

The amp definitely sounds better with the new chip but... me thinks someone is cookin the books
 
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