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NOS Tube Recommendation for Quicksilver Phono Pre Amp

I recently upgraded from the onboard phono stage in my Technics 1500SL to an all tube Quicksilver Phono Pre Amp. I’m about half way through the 30 hour recommended break-in period and so far, there is a lot to like about this piece of gear: Much thicker/more pronounced bottom end (I’ve had to readjust the gain on my subs quite a bit) and much wider/more defined sound stage. However, because I’m also running an all tube integrated amp (Raven Audio Osprey), there is now a very noticeable "warm" coloration to the music that wasn’t there before. I don’t want to give up on my new phono stage, but it’s like I’m listening to music with a wool blanket over my speakers. I’m thinking rolling the tubes to something a little cleaner/brighter could give me the best of all worlds. There are 3 tubes in the circuit topology: 2 12AX7s (one input, one gain) and 1 12AT7 (cathode follower). I’m currently considering a matched pair of Raytheon JRP black plate 12AX7s and either an RCA or Telefunken for the cathode follower (all NOS). Any and all suggestions/inputs are very much appreciated! P.S. my speakers are Raven Audio Corvus Reference Monitors and my current cart is the always amazing Nagaoka MP-500.

crawfishdaddi
dekay's avatar
dekay
5,507 posts
 

Not certain why, but phono input cables, tone arm wires and phono preamps take a lot of use to stabilize (sound as they will long term).

New small signal tubes in well used gear can take 10-50+ hours (maybe where QS’s 30 hours comes from).

There are gizmos (for low signal strength special EQ pathways) available that help simplify the process, but I’ve never tried them (Hagerman comes to mind).

I just wait and listen to music as far as TT’s go.

Here’s a link to the $50 Hagerman gizmo that you run a line source (CD/Tuner/???) through - instead of playing LP’s.

https://hagerman-audio-labs.myshopify.com/collections/accessories/products/iriaa2-inverse-riaa-filter

 

DeKay

 

 

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crawfishdaddi OP
20 posts
 

Thanks for the reply @larryi , yes - the loading on both the Technics onboard phono stage and the QS is 47k ohms (which is what the cart calls for). Unfortunately, neither have the ability to change loading settings. 
 

Regarding the telefunkens 12ax7, I’ve noticed there are several different types ranging in price dramatically. Do you have any experience/recommendations on specific type? Are the diamond bottom NOS several hundred dollars better than the standard telefunken 12ax7s?  

larryi
3,896 posts
 

The Telefunkens I run in my phono stage are the crazy expensive ECC 803S (equivalent of 12AX7).  I have heard others, but I don’t recall specifics.  

tomcy6's avatar
tomcy6
2,580 posts
 

Are the diamond bottom NOS several hundred dollars better than the standard telefunken 12ax7s?  

There are new production Telefunkens (Black Diamond) that share only the name with vintage German made Telefunkens.  I have no idea how the new ones sound, but probably very different from the old ones.

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