Doshi Phono Pre Tube Rolling

[dminches]

Hopefully people are both interested in reading this and providing their own feedback.

I have been running the phono pre for a couple weeks now with the stock tubes. The unit has settled in. I am using a Basis 2200 TT with a Benz LPS cartridge. The loading is set for 200.

I rolled in a pair of Telefunken 801s in the v3/v4 slots (12AT7). It is possible that these are truly NOS and need to be broken in but I did not like them at all. There was a lot of harshness in the female vocal frequency range and above, maybe up to 800 Hz.

Next, I rolled in a pair of Raytheon 5751s. Kind of got the same result. Harshness in the lower mids.

I put the stock tubes back in and the smoothness and warmth returned (with no drop off in detail).

I do have a broken in pair of 801s that I am using in my tape pre which I will try next. However, the stock 12at7s are the best sounding right now.

I have other tubes to try in the 7247 position and the 12ax7 position.

 

[dminches]

I have moved onto a pair of Mullard CV4024s and really like them.

 

[Bruce B]

I have moved onto a pair of Mullard CV4024s and really like them.

This is what I'm using in Nick's phono pre.... stellar!!!

 

[dminches]

Thanks Bruce. I thought I was talking to myself!

It sounds like you are using 2 Telefunken 803s in the 12ax7 spots. Those are very pricey.

 

[steve williams]

I use as quad matched set of Telefunken NOS ECC 801S.

I think you meant the same to Bruce because IIRC the Doshi tape pre uses 801's

 

[dminches]

I use as quad matched set of Telefunken NOS ECC 801S.

I think you meant the same to Bruce because IIRC the Doshi tape pre uses 801's

I think we are all using the ECC 801s in the tape pre but we have been discussing the phono pre which uses only 1 pair of 12at7s.

 

[steve williams]

I think we are all using the ECC 801s in the tape pre but we have been discussing the phono pre which uses only 1 pair of 12at7s.

stupid me

I wondered when you said you weren't liking the 801S