Hey Adrian,

Do you have the impedance switches on the more powerful setting? Steve says to go by sound, not specs...so with 6 ohm speakers, the 4 ohm setting your Torii (if it is built 4/8 ohm) will push your drivers more giving more body and weight. Also I guess you have played with the bass nobs? For me, those took a while to learn. And...does your amp have more than 600 hours? Bass develops slower and those caps are notorious for taking a long time.

Since the difference between 30 and 25 is pretty minor, little stuff might matter. There is a factor with the Toriis in how they communicate with different speakers, the way they ride the impedance to deliver power fully. Most folks that complain seem to have too much bass rather than too little, but since you had it before, I suspect you can get it.

In my room, I have to dump with eq with a shelf at 18 Hz (which slopes higher up) in order to solve too much below 32 or so. This was the case with my MKIII also and may be as much room as anything, but the information is definitely there. New HR-1s are rated to 32-22K. Mine were toward the end of pre-production before going up on the Decware site, and I don't think they have changed much, but I thought I recalled a little lower on bottom. I have not measured with an accurate enough setup to say what is happening here, but the low bass cut sounds better to me, cleaning up low/low muddle. The MKIV does not seem to role off but very slightly in the 15 range, and I bet the MKIII is similar.

Your rectifiers are probably Shuguang or Valve Art 274B (same tube though perhaps different selection). Some folks like them a lot, and the Preferred Shuguang series is supposed to sound better, but I don't know that. You will most likely get more micro information and extension with early RCA 5U4G-ST (coke bottle). The ones of those I have with deeper/bigger bass have thicker black plates, especially the space between the plates proper and the part of the plates the vertical wire goes up through...I think early 50s. Bottom getters on mine. I have some with top getters that are more open that I prefer, but I don't need deeper bass.

Sounds like you have nice VRs, RCAs are good. But make sure the coke bottle one is an OA3. If it is an OB3, it will push your power tubes less. This would be the place to start if it is not the more powerful OA3.

You will likely get a more solid, linear feeling sound from KT66. Genelex are extended and big/warm sounding, and Shuguang/Valve Art (TAD look like these) with most tube sets here are a more open/spacious but also extended. Lon has done a lot of exploring with his MkIIIs in this area, and I have not, but with my MKIV, I personally prefer KT66 or Tungsol 6L6G, which I think I recall is not your usual 6L6. I have not heard your particular EL34s, but I tend not to prefer EL34s, though many do, especially the Siemens/RFTs (different labels around E German made).

I have not explored the KT77 either, but it sounds like they tend to tighten up the bottom from reports. If you search this site you will find some comments.

Bass clarity and depth will improve if you happen to need cleaner power, or if you have vibration issues also.

Sorry not to more helpful with some specifics, but hope this helps some.

I agree with much that Will states.  I have pretty much followed what he and Lon propose in the way of tube compliment and am pretty happy with the sound across the spectrum.

I sometimes miss the dynamics of the 274Bs, but the RCAs are so rich and extended that I am sticking with them for now.

My only difference is the Reflektor silver shield 6n23ps I am using as input tubes on my Mk III.  To me they have more of an impact on the high end than the low end so I don't think that would help.  I do find the 6n1ps to be dull in comparison.

Sorry, I forgot about 6N1Ps being in there. I could never get them to work in the Torii due to early distortion in particular, but also lack of micro detail.

EH 6922 (black box) came with my MKIV and I was impressed with them during burnin, but have not gone back to compare in a long time. I remember them as "big" and extended with nice textured mids though. Extension and tighter sound is a characteristic of the 6922 family, but then they get quite variable, no two sounding alike in my experience. Also, there are anomalies in the other families. I just found some 59 Siemens CBS labelled 6DJ8s and they are amazing... warm, articulate, quite extended tubes, excellent nuance, with rich textures of good ECC88s.

Your description sounds like some of the tubes may have been losing steam. Comparing rectifiers will likely tell there. The 274Bs should go low. If you "went out" and bought tubes, I guess your tube store has a tester? Could be interesting.

The bass knobs do more than just bass...worth a listen now that they do something.

Don't know the vintage of your Russian rectifiers, but my 55's do have that Winged C vibe of big low bass, and enhanced mid-upper mids, a sort of classic sort of smooth "warmth" sound which could balance as leaner mid-bass. Worth comparing the 274Bs and see, that is if they are good. I am guessing more of the difference is the EHs, and that the 6N1Ps may be tired?

Have you cleaned your VR socket pins?

Lon (or Will), what are these magnets? Isolation devices?

Currently I'm using Ingress Audio (also fairly local to me) roller blocks on the amp, my DAC and he is making me custom feet for my speakers and an audio stand I'm making. They definitely do something under the amp and speakers! I don't currently have enough for both until my order is delivered, but I did a lot of experimenting today and decided I need them under that amp for now. They really tighten things up a bit.

Are they a specific manufacturer? The ingress feet definitely are the best things I've tried so far for tube amps, but admittedly do nothing but look cool under my DAC.

I've been using those magnets Will just provided a link to for a day now. I don't get to listen much on the weekends, so more experimentation next week but they're interesting with sound.

In my system the Ingress RollerBlocks under my amp robbed me of low bass. But I was using Mapleshade maple platforms and PS Audio PowerBases as well at the time, each system is different when combining stands and footers, and whether the floors are suspended or cement, etc. In my case I preferred the Herbie's Audio Lab Iso-Cups and now am using VooDoo Cable IsoPods under amp and components.