Author Topic: Rotel RQ-970BX Phono Stage - Andy Grove Mod  (Read 704 times)

Offline OldiesButGoodies

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Rotel RQ-970BX Phono Stage - Andy Grove Mod
« on: January 23, 2017, 08:31:40 PM »
Found one of these is good shape  at audioasylumtrader and bought it (this was after somehow killing my Emotiva SPS-1 stage by driving it with D cells - that is back in Tennessee getting repaired).  Sounded pretty good in stock form (well,  at least with my low output moving coil):

IMG_0579.jpg by Jose Sifontes, on Flickr

Then I found this "Andy Grove Upgrade" in the net:

So of course  started looking for parts and between my parts bin and raiding some of Tom's I found almost all that was needed and did the mod:

Audio by Jose Sifontes, on Flickr

I like the sound and the ability to change op amps.  The op amps I had in hand are not the exact ones called for by teh upgrade but I ordered those from Mouser and hope for further improvement.  The 2.45V voltage regulator is no longer manufactured so I ordered a 2.5V that should get me close enough to what mr. grove was trying to do to lower noise and improve gain characteristics.  For $200 total (including my labor,  billed,  at $5/hr) it is a pretty decent sounding phono stage. Wetted my appettite for the upper-class Rotel RHQ10.   O0



Phono: VPI Aries 1,  Van de Hul Frog
Cass: Tascam 122MkII
R2R: Revox B77
Sub: Rhythmik FV 15HP

Offline Jim Pittsburgh

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Re: Rotel RQ-970BX Phono Stage - Andy Grove Mod
« Reply #1 on: January 24, 2017, 08:41:30 AM »
cool project ....
Clearaudio Performance SEP/Talisman V2 gold,PL XP-15, Onkyo Integra DSP 8.3, Marantz SR6005, KEF Reference 5, KEF Reference 4C,KEF Q900, , Q800, HSU VFT-15H,Emptek DSA250,Krell S1500 #2 Marantz SR6007,  McIntosh1501, KEF Q600, Sunfire NHTsuper1s, Technics 1200 MkII/ Shure V15 xMR, dbx DX5 ,Jolida JD

Offline Bhope58122

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Re: Rotel RQ-970BX Phono Stage - Andy Grove Mod
« Reply #2 on: December 11, 2017, 10:24:54 AM »

Does anybody still have a copy of the Andy Grove mod? the link above is now defunct   ::)

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