Replacing The Stock EH 6SN7 Tubes For Cary SLP 05

Thanks for the replies. The post truncated before I cpould write my shortlist which is as follows.

After reading numerous online guides (including the reference one on Head Fi) I have a shortlist as follows (with my read impressions in brackets):

1. RCA 5692 Red Base - a long shot as this seems expensive (the best of the RCA's with a warm midrange, wide soundstage, smooth highs which are still somewhat extended, laid back and maybe rolled off)

2. Brimar 6SN7 GT - most likely the black base clear glass as the brown base dark glass one is probably too expensive (warm with a wide soundstage and smooth extended highs but more dynamic than the RCA sound)

3. Tungsol Black Glass Round Plates - again a long shot as it is probably over my budget (the best all rounder with all the above attributes quite balanced out)

4. RCA VT-231 Grey Glass (a poorer cousin of the 5692 red base with similar attributes at a lower price)

5. RCA 6SN7 GTB - (one more notch down in the RCA sound with similar attributes at a lower price)

Your opinions on how these tubes may sound in the Cary SLP 05 vis-a-vis each other is much appreciated especially from those with prior experience with the same equipment.

Thanks

Thanks for all the feedback so far.

Do preamp tubes need to be matched pairs? I keep getting conflicting opinions on this. Cary says yes but many others say only power tubes need matching.

Thanks Rodman,

Do I stick to the +/- 5% tolerance level in tube strength test levels for tubes that are manufactured around the same period? In other words, if I follow this, can I purchase loose tubes and then match them and adjust for imbalances using the balance controls on the pre?

The reason I'm asking is because many of the listings on eBay are for single tubes or multiple tubes that seem to be "loose". Even a lot of them that are said to be matched pairs have different appearances, date codes, labels, etc. but are said to be electrically matched.

I guess it's unfortunate that tube buying at reasonable prices seem to be a crapshoot.

Hi

Just an update.

I have tried using the RCA 6SN7 GT Grey Glass in the balanced input buffer positions with a quad of the stock EH in the positive and negative, left and right gain positions. This made the treble warmer and filled out the midrange - but probably a wee bit too much as some vocals got a bit chesty. I am guessing if I used RCA's all throughout it may be too much of a good thing. Using the stock EH in the balanced input buffer postions and a quad of RCA 6SN7 GT Grey Glass in the positive and negative, left and right gain positions did not do much to tame the bright treble - I am guessing the phase gain positions do not have as much of an impact as the balanced input positions(?).

I am trying to get a quad of early Sylvania 6SN7 GT's which are Chrome Domes but of the same construction as the 6SN7W's with black plates - has anyone heard these and how do you think they will sound with the RCA's in the balanced input buffer?