How close are your speakers to adjacent walls? Is it only boomy at higher volumes or at moderate volumes also?

Did you experiment with Height Adjustment off the floor as Zu suggests:

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I take it that u have tried the 2 possible bass settings?
Does the bass sound tighter at one setting?

Choosing another impedance setting can also help tighten the bass.
Have u tried that too?

Here is my room. Any suggestions are greatly appreciated!

http://i.imgur.com/hFrooGL.png

the doorway is actually opposite of the stereo.  not off to the side.  thats an apple panorama.

Would the Tung Sol 6L6-G work in the SE 34i.2+/Rachel?

Cheers,
Blake

Wow!  thanks for the suggestions guys.  i love this room.  it was my main focus when we bought the house.  i was also stoked that my wife thought my stereo should be the centerpiece of our living room.  

steve, i just bought some gold lion KT66s.  would have much rather bought the $149 tung sols.  i looked around for tube suggestions but was unsure where to go, so i just went with what was suggested in the manual.  i'd love to try those tubes.

not sure how i feel about the pads that go underneath my Omens, though i'll do my research.

thanks again guys!

R,

I personally think the Gold Lions are a lot better than the Tung-Sols but all rooms and systems are different. Bass will be different than with EL34s, will be interesting to see how they work out for you.

well i installed the KT66s and the boomy bass is gone.  but now i'm wondering "do i miss it????"  only time will tell...thanks for the info guys!

yeah.  big difference.  way more feel of the bass and less saturation of the bass.  wish i'd had these in the first place.

so the kt 66s have made a big difference in the sound.  it sounds more lush.  less boom to the bass.  what next?

Sounds like expected results from the Gold Lions. Nice tubes! What do you mean by what's next? What would you like to happen?

Isn't the MKIV amazing! Have you explored the switches fully. I did not like the Reconstructive Feedback until several hundred hours, but after that…I can't turn it off. Such a natural sounding lucidity here anyway.

Every tube effects the rest, and some are cheaper to explore than others but quite effective. What are you using now in all positions, and what is it you don't like about your sound and/or what would improve it….Is the bass where you want it now….tighter or fuller, mids richer/warmer or more transparent, highs smoother…clearer, more or less air…overall is the balance lucid enough… spacious/open or too dense….aside from an overall sense of density versus openness how is the tonal density…the notes themselves, not what is in-between…..if you can explain as clearly as you can what you would like and can make some suggestions.

roggae, so glad the bass problem has been solved and you are enjoying the amp so!

You can really BOND to these Decware amps. They become. . . dare I say it. . . almost like a family member! And they feel like heirloom products.

roggae,

Great pics. I was thinking you might have these tubes, but never know as Steve seems to move around at times when something comes up with quality or better sound or both. Also wondering if you could figure it out with the obscure russian markings.

So you have Chinese Ruby 5U4G-STs for rectifiers....Russian made OA3s, the Voltage regulator that filters the power tubes.... Russian OC2s, the Voltage regulator for the input tubes...and the inputs look like Russian 6N23P, a variant of the 6922/E88CC. Not that Russian covers it...there are different factories and vintages with variations in sound...but this is the base line and useful.

Do you have some thoughts about what you would like the sound improvements to be? There is a lot you could do, but some sense of what you are after would help....some of those sound areas I mentioned earlier could be good to think about.

what does changing out the OA3s and the OC2s do?

I have always preferred OB3s in the MKIII and IV for the less dense, more open sound, also taking the bass down a notch. The OC3 is a good option if you need more opening and bass calming. If you can get them reasonably, it would not be a bad thing to get a pair of both OB3 and OC3 in order to find your best sound and to have around for fine tuning. Though I have not tried OA2s, I agree with Lon, changing the OC2 is another good option for calming the bass while keeping a friendly sound. At least the RCA OB2s I have sound calmer, but still warm and textured. Both VRs will open things up some, causing a sense of increased transparency while also reducing bass density. I am doing a little direct comparison and will give a few suggestions later today, but have you looked at this thread:

https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1420057863/3#3

I would say try the GEs and the 5Y3GYs. The latter may reduce the bass a bit and the GEs may add some compensatory warmth.

Right, so let us know what the 5Y3s do for you. That will give a good indicator of how much the bass needs adjusting. Any of these changes, rectifiers and VRs basically adjust the density of the signal and therefore the bass, and typically the dynamics and tonal density. I was just trying some GZ34s, generally good for little sag, while opening with great dynamics and tighter bass (compared to 5U4G). With the OB3s (my standard), OB2 (new today), things got a little flat and lacking tonal density. So I put back in the 75C1s (like stock OC2s) and it is really good....open and fresh with nice tonal density but not that thick density that makes it sound dark and too full. Also tighter bass, and very nice textures.

Ooops. Well you have others to play with.

So here is what I heard today.

I am using Valve Art KT66 rather than Genalex, so a little different, but in the neighborhood. These are more open and transparent than the Genalex by a bit, with less push and body. Not a lot, but some. With them I have been using Mazda GZ32s, British made 75C1 (OC2), 40's Sylvania OB3, and various PCC88s for inputs.

I put in some 6N23Ps marked like yours and they sound quite good. A little more forgiving than my usual PCC88s, but a bit less spaciousness, micro detail, extension, and dynamics. For tighter bass, I put in some Zaerix (Hitachi) GZ34 rectifiers, but with the 6N23s they sounded pretty dull. With PCC88s, they were pretty nice. They did open things up and tighten bass, but the 6N23Ps being dull by comparison indicates a difference between 6N23Ps and PCC88s. GZ34s have always been seductive to me when I first put them in, but then they start seeming too taught.

So leaving the 6N23Ps in, I put in my "go-to" RCA 5U4G-STs with top “hanging” D getters…Different. These allowed really nice open textures and micro detail from the 6N23Ps, in fact bringing out beautiful tone from the russian inputs. The RCAs are a clear improvement over the Ruby's in delicacy, micro detail, texture.... Very good toward the end of true transparency, they probably will not reduce your bass much, though it would be more refined.

Then I changed the slightly warm 75C1 to the stock russian OC2. They brightened it up some...and similar to the Ruby/RCA rectifier difference, the stock VRs are a bit tighter and less complex, but they are good. They feel more clear than the 75C1s with the balance a bit more to the mids, upper mids and highs, but it is more just a balance difference than resolution, the 75C1s being really complete. The Russians seem like pretty nice tubes though, especially for less bass/more bright.

Next I pulled the Sylvania 40s OB3s putting in the stock Russian OA3. The balance shifted toward bigger, more forward mids and bass… increased overall density. This also gave a less refined quality, less micro detail and associated delicacy of tone...they are harder and feel a little veiled due to less micro detail, though they are pretty bright. The greater push and harder edges concentrate the sound too much here. The end result is less detail balance, with a harder, pushier, less textured quality. This is a similar problem as the Ruby compared to the RCA 5U4G ST, the Rubys having less refined character. So far two of your tubes could be improved toward pulling better tonal refinements from the source….things ultimately critical to a real feel.

Then I put back the Mazda GZ32s...Generally, these particular tubes are a touch warmer and more defined than the RCA 5U4G ST, but they balance with their own style of sweet micro detail, and their special clarified ambience. There is a little more sense of density to the clarity and dynamics, but in this case it does not sound harder. The midrange is balanced with natural, smooth highs and the bass is less and a bit tighter.

I think I recall that the GZ32 is sort of between the 5U4G ST and GZ34, and it sounds that way. This is hard to put my finger on, but I really like these tubes and they sound quite good with the Russian VRs and 6N23Ps. The Mazdas are my nicest GZ32s for bass tightness, open ambience, and natural tone, next being a fat straight bottle GE with black plates and a round top getter, similar but more bassy by a bit. Then the RCA 5V4G (coke bottle shape) can be really good too, but in my rooms this is my least favorite being a little thinner mids up and a little less taught mid-bass down. The bass comes across different with all of them and may or may not solve your particular bass buildup problem area, but they do seem to have less bass than 5U4G STs.

With the stronger feeling bass of the GE 5V4Gs, and my usual OB3s, I tried RCA OB2s replacing the front Russian OC2 VRs. Tightened up the bass a notch. Nice, but a little lean for me.

Finally I put back my 75C1s (OC2) and some really nice 50s Siemens PCC88 inputs. This is awesome. Bigger bass, but tighter....open and textured mids…greater tonal density, extended and smooth highs...beautiful ambience. This tube set is GE fat bottle 5V4G, Sylvania OB3, Valve Art KT66, 75C1s and Siemens PCC88s.

Finally, the OB3 and OC3 are the first tubes I would explore. You will get more open spaciousness, micro-detail, and more refined warmth with NOS OB3s. Then a notch more openness and less push with OC3s. The best OC3s I have are coke bottle ST shape Hytrons from the early 40s. Hytrons are in their own league for openness, delicacy, textures, slight warmth and other aspects of musicality, things for which several of your tubes are lacking in various ways for ultimate sound. The other OC3 that is really nice is a Sylvania OC3W, with the big brown base that takes up most of the tube. Some call these egg beater shapes. They are warmer than the Hytrons, but nice. For increasing your transparency, the Hytrons would likely be better.

It would be nice to get some 40's Sylvania OB3s and OC3s. One or the other will be best and there is only one way to find out! I was told by an experienced tube dealer that he thought all the OB3s are Sylvania no matter the label, and the 40s tubes can be identified by a D shaped stabilizer welded to the middle wire just up from the glass base, but this is hard to see in pictures since these have a low getter flash. I found that by looking carefully at the 3 wires coming up through the interior glass blob, just above the tube base...if the 3 wires are evenly spaced in the blob, they are 50s tubes and a touch warmer and more textured. If the middle wire is offset from center, these are the slightly more open and dynamic 40s tubes. They are all good though...

So toward your objective of transparency and tighter bass, I guess I am thinking that ideally you would replace the rest of your tubes other than the power tubes, perhaps the OC2s being the best if you keep one pair, and the 6N23Ps next. You will not regret changing the rectifiers and OA3s. Both are limiting your potential for open complexity and refined musicality, and this will very likely help your bass also.

Then, changing the 6N23Ps to some decent PCC88s....I almost always like them best. All I have tried are nice, but like all the tube types, they have different signatures. They are generally extended, open and textured, with relatively controlled bass, likely good things for your setting. Several more reliably rise to the top though.

My Bass was boomy with my Tekton Pendragons with the KT66's in my Torri4. So Steve suggested the Tungsol 6L6G's and man it sounds awesome now! Nice and super tight bass, big sound, even cleared it up big time! Thanks Steve!

are these basically what shipped with the mk4: http://www.thetubestore.com/Tubes/5U4-Tube-Types/Winged-C-SED-5U4-G-Black-Plate ?

better or worse?  i mean what should i get to replace my sketchy one(it's sparking inside on powerup and i can hear a faint scratchy sound for about a minute after it powers up)?  5y3? 5u4? basically i like the sound i'm getting now but i'm open to trying something different...thanks!

are those 274b tubes much bigger than the 5u4GTs?  with my kt 66s there is very little room between the rectifier and the power tube.

what about these: http://www.ebay.com/itm/Two-RCA-5U4G-Coke-Bottle-Audio-Guitar-Ham-Vacuum-Tubes-/...

what about these: http://www.ebay.com/itm/PAIR-BALANCED-5U4G-RCA-COKE-BOTTLE-BLACK-PLATE-RECTIFIER...

i can submit an offer.  thanks much for helping me navigate this myriad of options...

I agree, the RCA-STs and Valve Arts can be nice, though I liked Valve Arts better in the MKIII than the MKIV and the fit is a problem. The micro detail potential of the MKIV brings out the RCAs abilities in tonal complexity. But I like fine detail. And you may be able to get a good price on those Ebay ones, though they may jump a lot in the final minute. Do you know how to play that game? I often have someone go just over my high bid that I submit in the last few seconds.

Next to the Ruby's, I think RCA 5U4G-STs would be a notable upgrade in a similar sound balance though they vary some in bass density. The following are built just like my favorites. Mine have great balance and transparency and reveal everything with delicacy:

http://www.ebay.com/itm/PAIR-BALANCED-5U4G-RCA-COKE-BOTTLE-BLACK-PLATE-RECTIFIER...

I don't like it when sellers don't list the ratings, but they look good and clean, like a good match in how they are built, and the top D getter is a good sound in my experience. He says they are balanced and strong, which probably means they are good, especially since a lot of buyers like him. But if interested, I would write and ask for more information. What are the test scores and how do they relate to new and minimum scores.

Alternately the NOS Russians you are looking at from that period are popular and can sound good. I never loved them in the MKIII, and listening now in the MKIV first impressions are good ...textured detail and warmth though the bass is a bit too loose for me. Mine are 1955s. The bass not as defined as the RCAs and with the warmth, especially mids down....I am a little concerned that if you still have some low-mid/bass muddle at times, this could be an issue.

I think my current fav in the MKIV is still the Mazda GZ32 coke bottle (ST) shape, but it is not better than the RCA 5U4G-ST, just different.

From your pics I think your rectifiers are Chinese, Shuguang, sometimes labelled Ruby, and I guess those would be the tubes Decware would have for sale, but not positive. NOS RCAs are a different level with more complexity and natural timbre.

I don't think changing the OA3s would help the flashing. The rectifier is before them in the circuit I believe. Changing them from OA3 to OB3 or OC3s will progressively open your sound, reduce overall density and bass though if that is still an issue.

I am not sure about a light startup flash being an issue, I have put up with it happening occasionally with Valve Art 274Bs, but this does not mean it is OK. If you search the forum using Steve Deckert and 274, you will probably find a good post he made some time ago on the issue with 274s anyway.

But since you have a flashing rectifier that is also making noise, I would replace it asap. If it blows, the fuse should take care of things (at least it has when I have blown a rectifier), but then you would be out of music! Best to get to it I think.

I have both the Valve Arts 274B and the RCA 5u4g st in my MKIII and prefer the RCA for most music.  As Lon said the Valve Arts have a big bold sound.  The RCAs seem more refined.

No static = Good news

Sorry they are not an easy fit.

Not sure what is causing the need to turn the amp up more. Is it that the tubes seem quieter...or maybe less clear...darker might make them need more volume to get a good sense of the mids and highs.....what would you say? Different rectifiers can be a little louder or quieter, but 5U4G-STs should be pretty close electronically. Some NOS RCAs are bigger and darker than others, and warmer/darker than Ruby's, but I have not heard one that does not sound more refined...more solid, with better micro information and nuance. So it surprises me that you aren't hearing much sound difference with the new tubes other than the volume thing. Did the ones you got test NOS or near NOS? If they are true NOS, they will take a while to burn in and open up, and if they test low...well I don't know on that one. I have not used low testing rectifiers.

might look into a different pair of tubes actually.

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I posted the above early in this thread and have been following it for a while. Have not read every post in all 5 pages of this thread but it looks like many logical options have been implemented with limited success.

I still think there is a chance the bottom vented Zu's are coupling to the room in an odd way causing at least part of the Boom? Sweetwater ships fast & free of charge and accepts returns no questions asked. It would not cost much to try the Isolation Platforms.

Good Luck

the static is basically only present a few seconds after powering up.

I have a light round piece of wood about 3/8" in diameter and about 8 inches long. I have found that often a tube that produces intermittent static will produce the same static if you tap it lightly while the amp is powered up. I just go around and tap each tube lightly. This method has saved me a lot of tube swapping to find a bad tube.

Roggae,  I have isolation under everything including my speakers.  No boomy bass that I can hear.  I'm a big fan of isoation and my DIY platforms were cheap to make.  If you PM me an email address I will send you a few pictures of what I came up with.  I think the isolation helps with the sympathetic vibrations induced thrugh coupling of the speakers to the structure.  Seems like a good thing to avoid.

Hi roggae,

Last December I suggested the SubDude: Sweetwater can have a pair to you in a couple of days, $120.00 for the pair and free shipping. I'll pay the return shipping if they don't provide a significant improvement (I'm on the public record now). It's a sure bet for me and you will wish you had done it sooner.

http://www.sweetwater.com/store/detail/SubDudeII

Like Archie, I have isolation under everything (mains & subs) and it makes a big difference. The isolation platforms are especially effective with bottom vented speakers as you have.

ok, DBC i bought some off of amazon(free return shipping).  they will be here saturday.  we shall see!

right on, dbc.  right on.

I didn't re-read the whole thread so forgive me if this has been discussed but hardwoods are pretty tough to work with.

Bass traps?

Any corner you can fit one to start.

I don't have true bass traps but I lean 4 of those 2 X 4 acoustic panels across each of my two front corners.  I used to have them spread around the room, but it took away too much air and didn't really help the bass.  Then I stacked them in the front corners and it helped a lot.  

I also have triangle bass traps in all four of the upper corners.

I still struggle with bass in my room, but its better than it was.

This shot is before I consolidated them in the front corners:

Have you tried EL34s? Seems system/tube complement dependent, will above reports looser bass with EL34s, I find they have tighter, less copious bass in my system.

I think I would start by isolating all of the components.  I had  really bad feedback until I isolated my ZMA.  Also the spikes under the TT (if that's what the feet really are) seem counter intuitive.  I can pound on the support under my TT with no effect but I would think spikes would transmit any platform vibration into the component.  Is it possible that what you hear as bass boom might be related to feedback?

i thought it was component vibration too, but i'm getting it with every component regardless of its isolation.

tell me more about this inner tube idea?  i work in a bike shop.  i can basically get any size.

alright.  i've got the sub dudes in place.  i would say there is some perceptible difference, but the bass still seems to be kinda boomy.  i think it's just the room and i'm going to have to learn to live with it.

roggae,

Now that your bottom ported speakers are isolated from the floor they should be less sensitive to placement within the room. My point here is, speaker placement that did not work before may sound just fine now with the isolation? So you might want to experiment with placement again.

I know you have experimented with the gap under the speaker as Zu recommends. Once again, now that you have isolation from the floor you may be able to hear a bigger difference by adjusting the gap. Zu recommends anywhere between 1 mm and 16 mm (1 inch is approximately 25 mm), this is a wide range.

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so i decided i'd move my table today.  it sat on this home made shelving unit i made.  it served it's purpose in theory.  i noticed it had a fair amount of wobble every time i touched the table.  i moved the turntable to a much less mobile shelving unit and BOOM! bass becomes less flabby and resonate.  so i think this might be the fix.  it seems to make so much sense, but who knows?  right?

I agree with Will.  I have my amps and speakers on my home-built isolation platforms.  My TT is on it's stock feet which already give excellent isolation.  The TT isolation need is easy to understand; it's the amp isolation that I don't understand as well.  Must be something in the tubes?  I never had isolation with my SS amp.

I hope the BOOM stays GONE!

I also notice that the bass is less when I switch my voltage regulator tubes from OC2 to OB2. Sound is different, seems slower with more sparkle but sharper and leaner.  OC2 is fuller, faster more complete but also on some songs music resonates too much leading to a boomier bass.

JD