Rhea Noise

Like most Rhea owners in this forum I too have had tube issues since the day I purchased it; however, I recently purchased a VTV tube characterizer that solved my problems. I have been able to go through old tubes and find nice matched pairs that work in V1/V2. The VTV immediately screens out noisy or microphonic tubes.

I also learned some things from the good folks at Aesthetix that can save you money.

V1/V2 require longplates which are expensive if you want NOS matched, balanced, quiet non microphonic. But it was explained to me that V1R/V2R work as a pair that needs to be matched to V1L/V2L. For example assume that V1R is 100/100 and V2R is 90/90. These two tubes could be matched with V1L at 98/92 and V2L at 92/98. If you add the gain you get 95 for each of the four triodes which is what you want. Remember V1R + V2R = V1L + V2L

I've also found you don't need to match the gain perfectly as in my example but just get it as close as your ear can tell. The tubes don't need to be perfectly balanced either but probably should be within 10%. They key is that they not be noisy. Nosiy tubes sound like wind and it's not tube rush because it varies in volume intensity. I have found that tubes that sounded slightly microphonic can work well too. More microphonic ones can sometimes be helped with a Herbies damper but really microphonic tubes ring when I touch the chassis.

Having said all that the Sovtek LPS are the quietest tubes I've tested so far. I got lucky with NOS tubes. I found some NOS early 50's Philips longplates that tested absolutely perfect as well as a few pairs of perfect Mullard 10M's, one pair of which is in V3 and the other in my Calypso. None of these NOS tubes were more quiet than the Sovteks but they were just about equal. I have some matched Brimar CV4004's in V4 and Philips 7308 SQ in V5.

I've had this setup for about a week now and I'm still pinching myself. After six months of one tube hassle after another some of which were of my own doing, I'm now in audio nirvana. The Philips tubes are 3D like. This is not the same Rhea I purchased. It sounds awesome now as opposed to great when it was working before. The noise is not an issue and I'm using an .24mv Airy at 68db balanced. It also works at 75db rca but it pops at 75db balanced. I'm not sure whether it's supposed to work at 75db balanced or not.

I wish I'd bought the VTV right away. It's expensive but it will pay for itself in the long.

My Rhea is extremely quiet and sounds wonderful with a 0.5 mV cartridge. It is hard for me to understand why there is so much negative comment on this thread about this fine phono stage. Are some of you guys trying to run sub 0.1 mV carts on your Rheas? Why? What advantages do they provide that 0.1 to 0.5 mV carts don't provide? This super low ouput stuff makes me wonder a bit only because then the limiting factor has to be the arm/table and phono pre. I mean I understand the pursuit of excellence here but I have never been convinced that a super low output cart is advantageous.

Something that everyone here needs to understand is that whenever you use a pure tube signal path as a gain source for low output MC cartridges, there will be noise compared to either a fet/tube hybrid gain stage or a pure SS gain stage. The tradeoff for some added noise IMO is a much more live sounding phono stage that doesn't sound flat and two dimensional like its SS brethern. It is imperative that you buy tubes that are graded for noise by a competent dealer such as RAM labs or Kevin Deal or in my case, Michael Elliott of Alta Vista. I use the Counterpoint SA-2 MC pre-preamp and it is pure tube including the rectifier and voltage regulation. I buy the highest grade 6922 tubes that Michael Elliot sells for the SA-2. Only 2 out of 100 tubes makes this cut which is why you pay a premium for them. Buying expensive "super" tubes such as Amperex, Telefunken, etc. which are not graded for noise is a pig-in-a-poke purchase. It doesen't matter how "great" they are if they are noisey.

For what it is worth I would not trade my Rhea for anything.....well maybe a Manley since I have their mono-blocks but other than that nothing. My noise issues have been completely managed since my original post. Once again I salute their tech support.

Dear amigo Raul,
You unfortunately wrote, "The fact that many people ( like you ) likes the heavy distorted and colored tube sound does not means that is the right way to go."

Come on, man. That is way over the top. The argument against this notion is too old even for me to bother to reiterate it. In this day and age, transistors and tubes can both be used to build fabulous gear. For very low voltage input signals, like those emanating from LOMC phono cartridges, a transistor circuit has some advantages in terms of noise. Period.