tube preamp in SS receiver loop

I seem to agree with some of the principles here, but not many of the recommendations. Keeping the signal simple is a good one. Ditching the mid-fi receiver is another (sorry).
Aside from a vinyl record player, most input devices, even quite ancient ones e.g. cassette, reel to reel output at "line level" of around 1v and have fairly standard output impedance (a bit brave, but bear with me). Some newer inputs e.g. DVD, BD, DAB may substantially exceed this (often up to 2v). Consider what a pre-amp "does". Given decent inputs, all a pre-amp really does is to switch from one input to another and adjust the volume (downwards) from line level (or whatever the input level is). So all you need is an input switch and a volume control, neither of which involves tubes at all. It is partly audio "philosophy" but IMHO, at best a pre-amp should be passive and should interfere as little as possible with the sound. So, you can get high quality input switching modules from China with gold-plated relay contacts for $25 (e-Bay). You can spend $700 on a Stephens&Billington transformer-based volume control or $500 on a fixed resistor stepped volume control, both of which are excellent solutions, however, on a budget, the best value for money solution I know is a motorised ALPS Blue-velvet volume control from Germany for $35. You can then get a remote control board and transmitter to switch the inputs and control the volume via the motor from your armchair for another $20 (e-Bay). This leaves 2½ issues: Phono stage - get a cheap solid state stand-alone one for $30 e.g. http://www.maplin.co.uk/stereo-phono-pre-amplifier-28732 . You can spend $000's on a phono stage, but we are just experimenting here, right? Second issue, tone control: Tone control should only be used to correct deficiencies in input quality. It is not required for phono, any digital input like CD or FM radio. It can be useful with poor cassette tapes or reel to reel tapes which have deteriorated over time and repeated playback. Again here, what adjusts tone is essentially inductance, capacitance and resistance (LCR) networks - no tubes. These are pretty simple, but if you don't feel comfortable making them, you can probably get a cheap solid state or passive unit. Plug it in between your deficient input and the switching unit. This yanks the budget up a bit, but Musical Fidelity offer a stand-alone tube-based tone control unit called an X-Tone. You can get one of these (the Mark 2 version) for around $200 on e-Bay. Last issue - impedance-matching: All this takes is two resistors per device before the input switch - again no tubes - and I would venture to guess you won't need to do it anyway.
So we have elimiated a lot of noise and distortion (and tubes) from the pre-amp zone. If you still want tubes (I use them), you could get a tube-based power amp. You can get an entry-level built module from China (e-Bay) for $45 or a more professional finished version in a case for $200. You can probably find some worthwhile tweaks and mods on the internet if you want to upgrade this to sound better.

I have a Linn, Majik DSM which is an excellent digital music player, (integrated), with all components connected to use it's volume and switching, (and great DAC), and then fed via pre-out to a MasterSound 300BPSE which is also an excellent, Italian integrated which I am only using the Line-in so it's role is strickly amp.

The sound is pure and magical. No coloring but the staging and separation is the best my aging ears have ever heard.

Higher end than what your testing but an excellent higher mid-range configuration that simply delivers beautiful sound, (and the amp is only 24 watt)!

My speakers are custom built, (based on SEAS Exotics), and at 91db efficiency, let me hear if anything is amiss and so far, the only disappointment has been some the tubes I have purchased, but then that has also allowed me to find a combination that has had me in tears of joy.

Your idea works and delivers beautiful sound.

Cheers

Bob

Grant Audio used to have the P-307, which is like the MkII 283 but has a phono input. http://shop.grantfidelity.com/Grant-Fidelity-P-307-Tube-Phono-Pre-amp.html

It's now unavailable but you should write and ask them about it.

You can get basically the same thing but without Grant branding and quality control at:
http://audio4lessonline.com/Yaqin_MS_22B_Tube_Phono_Stage_Amplifier.html

I have had great success with 2 Grant Fidelity tube buffers. The smaller 283 in my office system, and the MKII 283 in my main system. I've updated the tubes to cryo-treated, and use a decent power cable. I have them between the DAC and the Preamp.

I only use them between the digital sources, not analog, and the preamp. After all, that is what needs the most help. It works wonderfully, and only cost $350 with upgraded tubes for the MKII.

Another inexpensive option if you want to go preamp, is the Jolida JD5T. Tube preamp, with remote, for $425 new.

Enjoy,
Mot

I am very grateful for all of your thoughtful responses, and am learning a lot! I have been away from all this for a few weeks due to a frantic new job with ungodly deadlines, and before reading some of the more recent posts here -- in fact not realizing they WERE here -- I acted on the Yaqin ms12b tube phono stage and line preamp, which arrived the other day. If it doesn't work for me, it can go on sale. I would like to have the money to do better than trying to cobble it together with my modest vintage SS receiver, but maybe that will come with time.

I've just begun to experiment (a wonderful way of not worrying about work!). What I have discovered: If I plug the Yaqin directly into my receiver's PRE-OUT MAIN-IN loop, all the receiver's tone and volume controls are disabled for the phono, which of course goes directly from the RIAA input on the Yaqin preamp to the solid state MAIN IN. Tone and volume do work for other sources, I guess because they go through the SS preamp before going into the Yaqin, and I do have the Yaqin volume control.

If I plug the receiver's TAPE OUT into the Yaqin LINE IN and the Yaqin output into the receiver's MAIN IN, resulting in a TAPE OUT-MAIN IN loop, the receiver's tone controls are bypassed for all sources and the receiver seems to act as a source selector without modifying the signal, so that might be the purest solution. But I may still need tone controls at this point.

So far, with the Yaqin going directly into the power amp--without the use of tone controls and the ability to temper the treble--I find it harsh and tinny, much more so than the SS receiver on its own--which I was trying to mellow and soften. (I am not yet a purist!) Of course, I still have new stock Chinese tubes in it, which are not supposed to be all that great.

On the other hand, if I put the Yaqin into the Marantz TAPE-IN TAP-OUT loop, where I have the advantage of the receiver's tone and volume controls, the sound is more pleasing--still not sure how much better it is than the plain ol' Marantz is, but maybe tube rolling, which I have never tried, might be the next step.

This is all quite confusing to me, and one day I may bite the bullet and go for an integrated tube amp. But in the meantime, what about just leaving the tube pre-amp in the tape loop, with access to the receiver's tone and volume controls? At least for now? Followed with better tubes fro the Yaqin.

Or can anyone think of a better configuration? Thanks, all, for sharing your knowledge and expertise.