Reviews of the BA312 Vintage Marantz upgrade modules from the Audio Karma forum

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The Sparkos Labs BA312-M upgrade modules for Vintage Marantz and Sansui Receivers have been reviewed by several members on the internet audio forum Audio Karma. These upgrade modules allow our SS3601 discrete op amp to be installed in place of the old BA312 preamp IC in these classic units. Below are some highlights, excerpts from the threads, pictures, and measurements that the Audio Karma members have posted. We also put links back to the original threads on Audio Karma so you can see the them yourself. We wanted to thank all of the Audio Karma members who took the time to make these posts and share their experience with the BA312 upgrade modules!

Member Echoplex said : I installed the BA312-M 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. 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.  I know right now that 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 in my Vintage Marantz Receiver.

Vintage marantz BA312-M upgrade

Member Rhodus said : I installed a set on my 2285 several months ago and I agree with Echoplex. It is a definite improvement.  The op amps are a must have. They are a profound improvement in sound quality without losing that "Vintage Marantz soul."

User Raidermc said : I installed some Sparkos Labs 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.

User JFlijohn said: I blowed up my stock 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.

sparkos labs vintage Marantz audio upgrade

Member rBuckner made and posted the following measurements comparing the original BA312 IC to the Sparkos Labs BA312-M Vintage Marantz upgrade.  It was concluded that the BA312 upgrade modules yielded a 10dB (roughly 3X) reduction in noise and approximately a 2 - 3 X reduction in distortion (THD+n)

Vintage marantz upgrade measurments

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