2B TL mod, finally

headrott

I find that it really depends on the gear you use along with the speakers and the crossovers. When I change out the tubes in my DAC and pre-amp, it really has a large affect on the output to the amp and the speakers. If I use some RCA black plate 12AX7's in the DAC and some Siemens CCa's in the BAT pre-amp the highs are definately more rolled off compared to using some Valvo 45 degree halo getter 12AX7's in the DAC and Siemens CCa's in the BAT pre-amp. I found the best combo for the 2.3TL's is the RCA Black Plate 12AX7's in the DAC and some Amperex D-getter 6DJ8's in the BAT pre-amp. this goes to show you what just tube rolling can have on the sound, let alone the actual equipment itself. Not to mention cables having an affect on the sound. So, it depends on what else is going on in your system that determines what value of resistor in the polyswitch spot. In the wise words of madmax: "everything matters".

Greg

gmcman

Now I only have about 20 hours on the recap and understand I need many hours....but i'm curious as to how drastic the differences are within the first 100 hours or so.

Reason I ask is I put on a very familiar CD..Dire Straits "On Every Street" and I noticed Knopflers vocals were higher than what I was used to hearing...almost a "hollow...tinny" sound, the soundstage seemed slightly narrower and the instruments seemed to be more centralized except for a few of the songs where they are very wide and that was still noticeable.

So different that I pulled the drivers to ensure that the polarity was correct.

Just wanted to ask, but time will tell. I know the gear makes a difference but overall the clarity is higher and the bass is much more pronounced.

Conradicles

My Monitor 7A's have been buring in since Monday, so they have about 96 hours on them. I used Jantzen caps and Mundorf resistors. I have listened every night this week and they keep getting better and better. The "Tiny Hollow" sound was there a little in the beginning but totally gone now. Bass is also extremely better as of last night, but I got much more listening to do this weekend.

Joe08867

The difference between 10hrs and 100hrs is quite drastic and then again somewhat drastic at 200hrs.

Give it time to mellow out. You have all new components in there that need to get used to there new life.

inspiredsports

quadzilla wrote: »

har. dee. har. har. But then, my dad always enjoyed his AM radio with the tone knob turned all the way down. Maybe you point five guys are like that? :razz:

I think you are missing the point that the specific architecture of your crossover and interconnect cable come into play, and that Polk used .50 poly's in many (if not most) of the iterations of 2B's that they produced.

quadzilla

Nope, not missing that.

inspiredsports

quadzilla wrote: »

Nope, not missing that.

Then it would be fair to say your attempt at razzing us ".50 guys" in post #31 kind of misses the mark

quadzilla

No, what I'm saying is that the CRS+/SDA 2B originally had SL2000 tweeters with their spiffy response knee. After TL'ing these speakers, .5 seems to be too much in the polyswitch spot. But as I've said so many times now, that's by my preference. You can put a gigaohm resistor in there for all I care if that's what sounds good to you.

Or did you just miss the smiley?

gmcman

I have them on a 2-week plan to just keep playing, having read through other threads i just was curious basically on the level of change and the term "drastic" comes up alot.

On the 4th day I let them play through the night and the next day and told the LOML to keep them on, but could switch to TV if she wanted. I came home and went downstairs with the 3YO, sat on the sofa and granted the lights were still out and I immediately noticed a loss in treble, deeper bass and was remembering a few posts on how they get better, then worse, then better and how someone commented on the fact the .5 sounds like a cover was over the tweeters.

I'm thinking,...."the .5 mills has to go, no way can this get better" I sat through the song and was thinking on having to go in and pull the resistor possibly after the break-in. I went up to the CD player, granted the lights were out... and realized I had a thick sweatshirt draped over the front of the speakers to cut down on the sound. :redface:....long day at work.

They are now in a room by themselves, facing each other, with a few pieces of rockwool around them and they can argue with each other for the next few weeks. I don't need anymore surprises....ha.

heiney9

Your not far enough along to start changing things like removing the .5 mills yet. Give it a full month of listening.

H9

gmcman

heiney9 wrote: »

Your not far enough along to start changing things like removing the .5 mills yet. Give it a full month of listening.

H9

Oh no.....i'm not switching anything, that was just my initial reaction to my "duh-moment"

They will be playing for another 200 hours or so before I even hook them back up.

gmcman

Just had to post the final pic, these boards are awesome...thanks Tony!

Will go back and tie the caps down against the foam after the burn-in, per recommendation.

quadzilla

Very nice work.

gmcman

So I buckled at the knees and replaced them into general population at 100 hours. I needed to rearrange the listening area and center the components...the corner-loading of everything just wasn't cutting it, now I just need to add a door to the adjacent room but no big deal.

There is a noticeable difference, much smoother but still slightly bright....not that it really bothers me so we'll see how much more they settle after another hundred. The wifey noticed the improvement so that's an added bonus.


Hypothetically speaking......what would happen to the overall tone, x-over characteristics, if there was a 5.6 uF in place of the 5.8?

gmcman

Reason I ask, I was concerned as to the likely misprint on the cap. I called Sonicap and they said they found some mis-labeled caps and this was indeed a 5.8..looks like a 5.6 on the cap though.

Not sure how accurate my Fluke 89IV is at measuring capacitors but it does read 5.80 so I guess I will let it be.

evhudsons

gmcman wrote: »

Hypothetically speaking......what would happen to the overall tone, x-over characteristics, if there was a 5.6 uF in place of the 5.8?

I would like to know too. Does anyone have experience in either 5.6 uF or 6 uF?

Face

Most end up using a 5.8uf, it sounds fine and is within tolerance.

evhudsons

I'm asking because trey used either a 5.6 or a 6 in order to stick with clarity caps. He did give the option to use a 5.8 Sonicap

I'm happy with my sound, but it does seem so much brighter than before upgrading the crossovers that I wondered if it was due that varience. That's why I wondered how or in what way the sound would change.

gmcman

The last 60 hours or so have been mainly TV or HT however you wish to call it. Played a few albums and it still appears to have a slight bias towards the tweeter, just slightly bright. The overall sound is very smooth, guitar strings, soft vocal passages are very detailed and not harsh. My ears are just wanting to hear the highs dip down slightly into the mids, just very slightly though.

There seems to be a slight lack if richness in the male vocals, I wish I could explain in better but that's probably as best as I can describe it. This is why i'm looking into a room eq setup to see if my ears are playing tricks or something.

I suppose I could say the mids aren't bright and the highs need to be padded a bit more. I guess I could change the resistor but I don't want a franken either.

Speaker cable is AQ Crystal if that is a possible culprit.

Any ideas?

heiney9

What you are most likely noticing is the new x-overs are more neutral compared to the old worn ones.

H9

audiocr381ve

heiney9 wrote: »

What you are most likely noticing is the new x-overs are more neutral compared to the old worn ones.

H9

This and just give it more time. I've done 2 crossovers now for my 2BTL's and they need several weeks. I don't have a resistor in place of the polyswitch and the highs are perfect. With the .5 in there they'll definitely sound padded down in a few weeks. Keep listening/evaluating.