[speedcenter]

I have thought of isolating my CDP using a plate of 1/2" lexan and some vibrapods.  I just haven't made the plunge.  Not that expensive, really.  My mom works at an idustrial supply house.  I can buy a 4'x8' sheet of 1/2" lexan for 135 bucks.  Way more than I need.
...
My wife is giving me some hard stares lately everytime I mention upgrading another component.  "

Just start with a more affordable experiment - $135 for that is well beyond anything I'd spend myself.

Start with a fat piece of MDF from Home Depot. Get a piece of plywood cut to the same size, matching your CD player dimensions. Glue those boards two into a sandwich (so far about $5 max). Then get a 12" bicycle inner tube - about $3 each. Place the inner tube on your rack, inflate very lightly, place MDF/plywood platform on top.

On top of that platform, place  three "super balls" ($0.50 each at Toys-R-Us). you can keep those from rolling away with small rubber bands or something else placed around them.  On top of the balls place the CD player. One ball under transport, other under power supply, third placed to balance it out.

This should already sound real nice, but you can experiment with weight loading (I used three small paving bricks) on top of the player. Some people say this just moves the problem frequencies lower, but it sounded better to me, and that's all that counts for a low$ tweak.

Make sure the wires and power cord are nice and loose, possibly curved in a C-line to allow as much free motion to the player as possible.

Another design would be to drop the super balls and replace them with a DIY rollerblock design: 3 large soop spoons, handle cut off, secured on top of the mdf board with window putty. Place 1/2" steel balls in spoons and balance CD player on those.

the only problem I see with these tweaks is the WAF (wife acceptance factor) regarding the "look" of the setup  

But trying these tweaks is dramatically cheaper than spending big bucks on a fat piece of lexan, and they may yield results better than you think.

Peter

[hammergjh]

Ok, I hope I did this right.  I tested the DC voltage across the speaker terminals w/ the amp and preamp on but no music playing.  I got readings between 2 and 4 millivolts.  As a source was turned on and the volume slowly increased I got readings as high as 20 millivolts.  They were fleeting, however.  Now, the meter is a self ranging digital type, and it was jumping around quite a bit under both conditions.  So, well, I dunno.  Any comments?

[mgalusha]

Ok, I hope I did this right.  I tested the DC voltage across the speaker terminals w/ the amp and preamp on but no music playing.  I got readings between 2 and 4 millivolts.  As a source was turned on and the volume slowly increased I got readings as high as 20 millivolts.  They were fleeting, however.  Now, the meter is a self ranging digital type, and it was jumping around quite a bit under both conditions.  So, well, I dunno.  Any comments?

A few milivolts is fine. Since it increased with volume it's possible your preamp has some DC offset. To accurately measure the DC offset you should disconnect the pre from the Stratos and then power the amp back up. When first powered up mine will read around 90 mV and quickly drop to near zero as the circuit stabilizes. It may vary a little depending on how warm them amp is unless the bias is temperature compensated.

You may wish to check your preamp for any DC as well. Feeding DC into the Stratos is probably not a good idea as I believe it's direct coupled.

HTH,

Mike

[wreilly]

Mike wrote:
_______________________________________ ______________
A few milivolts is fine. Since it increased with volume it's possible your preamp has some DC offset. To accurately measure the DC offset you should disconnect the pre from the Stratos and then power the amp back up. When first powered up mine will read around 90 mV and quickly drop to near zero as the circuit stabilizes. It may vary a little depending on how warm them amp is unless the bias is temperature compensated.

You may wish to check your preamp for any DC as well. Feeding DC into the Stratos is probably not a good idea as I believe it's direct coupled.

_______________________________________ ___________________

This is true and Mike has offered "sound" advice.

Also it is true a few milivolts will not make any difference as long as it does not exceed the point at which the voice coils start being displaced.
What I was concerned about was that if there were enough DC voltage at the speakers it would be driving ( holding ) them away from there null position; thus cousing distortion when played at high volumes.

While 20mv is probably more than I would acccept it may be fine in your system. Much of this depends on the crossover in the B&W. It may block the DC altogether.
As I said there are many variables.

And as I said before I think you may be overdriving the B&W.
This is difficult to determin but say your volume dial goes from 0 - 10.
At what position is the sound OK and when does it become distorted?

Regards,
Bill

BTW: My EAD PM1000 has <1 MV regardless of the input volume level.
Just for comparison.

[hammergjh]

The B&K has 40 steps on the attenuator in 2 Db increments.  The display shows as follows:

-70 Db (muted) --> 0 Db --> +8 Db

After the first week w/ the Monster IC's:  I couldn't get it much over 20 Db's w/o it sounding fairly distorted.  The Hafler could go up over -10 Db's easily, close to 0 Db on the scale.  (It's damn loud at this point.  My wife can't be home when I do this.).

After 2 weeks w/ the Monster IC's: maybe a little better.  Not much.

After 3 weeks w/ the Van den Hul IC's: I can get it up to -14 or -12 Db's before it starts to distort, maybe up to -10 Db's on an instrumental track.  The vocals seem to be the toughest part of the music to portray.  So I see a definite improvement.

Could be 2 things causing this improvement: the new IC's and the amp's "break in" is occurring.  So a positive.  

As far as the DC voltage with some gain (playing music) at the speaker terminals, the 20 mV was very fleeting.  The digital voltmeter's readout was dancing quite a bit.  The average was probably close to 10 mV.  I'll check the DC voltage from the pre tonight.  I believe I should be checking the voltage across the RCA jack by putting one probe in the hole and the other on the outside of the jack, correct?  I'll report what I find this evening.  

BTW, Bill, I think you're right.  I do think I'm overdriving the B&W's.  I'm not trying to, I'm trying to find out what the amp can do.  You're also right about the Hafler not putting out the same amount of power.  But, why can I turn the Hafler up louder on the preamp than the Odyssey before it starts clipping?  Does the Odyssey clip earlier?

Thanks again for posting some great feedback for me.

[rosconey]

kinda stinks you still arent a happy camper.
my mono ex's dont ever sound distorted,maybe the hafler is the amp for you. your so used to it now.
i'm using my yamaha rxv1 as a pre with mine, my speakers are 3.5 ways rated at 100 watts designed by rick craig, my old amp was rated higher power but the monos are more powerful or so it seems to me.
my old amp was a carver pm350(350watts at 8 ohm)
have you used a sound meter to check output from bolth sides? maybe ups screwed up one mono a little.
i love my mono's wish you could say the same

anyone see the gold mono's on audiogon-wow they look sharp, i love the different style cooling fins.

[hammergjh]

Just to clarify, I'm not displeased.  It's definitely getting better.  The system sounds nice, pretty good, really.  I thought, for the money, it would sound awesome, though.  Maybe it will in time.  As stated by someone earlier, there are lots of variables here.  Mid-fi CDP, questionable preamp.  Speaker wires???  Tweaks.  I've been upgrading my system for the past year, and as we all know in this hobby, we are never pleased until the next upgrade goes in.  

Tweeter, a big chain in the east, sells a lot of mid fi crap and some, but not much, good stuff.  I wasn't thrilled w/ the stuff (pre & cdp, IC's and wire) I bought from them last spring.  Maybe I goofed and didn't return it all back then.  Probably got lazy.  Well it's a learning experience, at the very least.  

A lot of what we buy is based on some faith.  Mail ordering equip. is a little risky.  I'm going on total faith here on my Odyssey purchase.  Tons of positive reviews, almost no negative reviews.  I thought at this price point it would work out.  Vs., say, the Bryston or Classe equipment, among others.  Not to say the Stratos ISN'T working out.  There are some dealers in the Boston area w/ some good stuff for sale, but it always sounds different once you get the equip. home.  That's why they all offer a return policy, right?  

Still listening to the music.  That's why we buy this stuff.

[BlackCat]

hammergjh:
I'm driving my B&W 604 S3's with XT monoblocks, the 604's are power rated about the same as your speaks, I can turn the thing up to arc-welding power with no distortion from the speaks.

[wreilly]

Greg,

Hmmm...the plot thickens. Blackcat has thrown a wrench into the works.

His B&W do indeed have the same power ratings. Well anyway I do this backwards starting at the output working back to the inputs; old habit.
This may indeed be the much talked about breakin period. But I doubt it.

However now we are at the hard part. It could be that the signal is clipping at the input to the Odyssey. In other words we are overdriving the B&K.

The B&K has the following:
Max output = 8 v RMS
Output Impedance = 221 Ohms

I canot find the specs for the Hafler, perhaps you have them.
Also there are no specs for the input sensitivity and impedance on the Odyssy, perhaps Klaus can help here.
It is possable, though unlikly, they are just mismatched components.

Let's see if we can collect some additional info.

I can not wait to try out the DM with my system. The DM is going to be used to power Aerial LR5s with an Aragon Stage One Pre-Pro. The Aerials are very demanding.
I'm having a hard time waiting till the 28th to get a shipping date from Klaus.

Regards,
Bill

[speedcenter]

Just to clarify,

I thought at this price point it would work out.  Vs., say, the Bryston or Classe equipment, among others.  Not to say the Stratos ISN'T working out.

Just imagine you had just dropped $4k on a Bryston and it woudln't even sound as good as what you have right now... I don't think there's a Bryston forum you could go to and vent

let it break in - takes some time I am told. I got my Odyssey Monos used one year old, so the wow experience was a little more immediate

[hammergjh]

Here's a fairly technical review on the Hafler.  I'll check my manuals out tonight and try to post some more data.

http://www.hogheaven.com/diyaudio/projects/DH200/DH200review.html

[scottpretti]

Have you tried a different and/or better CDP. I've been using a "new tube 4000" forgot the spelling, with EAD Ovation Plus,  Northcreek Okara II speakers, DIY cat5 speaker cables and kimberkable ICs.  Never had  problems at any volume levels.  The Stratos Stereo in my set up sounds phenomenal.  I've also had the Stratos hooked up to my Adire audio 281's with no signs of problems.

[W.C.]

Have you tried positioning your speakers about 3' in  from the wall that's behind them and about 3' in from the side walls? You might try to toe  them in slightly also. If this changes the sound, in what way?

[wreilly]

The more i think about this, I think this may be the problem:
The B&K has the following:
Max output = 8 v RMS
Output Impedance = 221 Ohms

An output Impeadance of 221 ohms is very high, most ss pramps today have something on the order of 25 - 50 ohms. Classe claims zero...this would be the ideal; all of the output from the pre is transfer without loss.

It is possable that the output of the B&K is reaching its 8V output "too soon". Clipping at the input of the power amp. GIGO, sorry.
 We need the input impeadance of the Odyssey, If it is high enough say 10k or higher, then this is not the problem. Since this is impeadance and thus frequency dependent this cannot be measured accuratly without a scope. However if you have a scope you can watch the pramp output signal as the volume is increased. Clipping will be seen as a squaring ( flat ) at the peak of the signal. If you hav a test CD the produces pure tones this would be much better.


Klaus if you listening in we need you help.

Regards,
Bill

[hammergjh]

Hi, here's some data on the Hafler.

< .015% THD up to 100 watts 20 Hz to 20 khz both channels at 8 ohms.
 Freq response: -3 dB 1 Hz to 100 kHz at 1 watt
                       +-1.5dB 10 Hz to 40 kHz at 100 watts
Channel separation:> 60 dB's
S/N: > 100 dB's at 100 watts into 8 ohms
input impedance: 22k ohms
input sensitivity: 1.5 volts rms for 100 watts into 8 ohms
damping factor: 150 to 1 kHz into 8 ohms
                          50 to 10 kHz into 8 ohms
slew rate: 10 kHz, 60 volts: 30 V/micro second.

Some of these specs seem pretty good.  Others, just so-so.

BTW, I contacted Monster re: the speaker wires.  They are copper, although they are "tinted silver color for cosmetic purposes".  I have another question as to what the copper is tinted with.  Will let everyone know.  I'm looking into some speaker cables.  There are a few around that don't cost an arm and a leg.  DH labs seem reasonable.  I was thinking of some more VDH product as their stuff seems of very high quality.

I've been burning in the VDH IC's and amp, no real listening lately.  Will keep everyone posted.  I do appreciate everyone's great feedback and advice.

Thanks.

[hammergjh]

Howdy,
   Here's link on the VDH IC's I'm now using.  

http://www.vandenhul.com/cable/d-102-3h.htm

Thanks.

[BlackCat]

hammergjh:

I doubt the VDH IC's are the problem, they are very highly regarded on audioreview.com - getting an impressive 4.58 / 5.0 from 40 reviewers.  There does seem to be some concern there with equipment compatibility, you'll have to read all the reviews to see what they're saying.

    http://www.audioreview.com/Cables/Van,den,Hul,Van,Den,Hul,D102III/PRD_116683_1584crx.aspx

We've been talking a lot about the sound from your CDP, do you see this same behaviour from your vinyl rig?

Also, my next culprit would be that speaker wire you have there.  Monster cable is IMHO, crap. (others may throw stones now)  Take a look at the DH Labs T-14 speaker wire, highly regarded, won't cost you a Friday night at a whorehouse.  Also at:

http://www.hcmaudio.com/homeimages/cc.html

They have the Nordost Super Flatline and Flatline speaker cable at very good prices.  Change that stuff out and see if you hear a difference, it should be an improvement approximately equal to what your heard when you put in the VDH IC's, or better.

Just my 2 cents.

[hammergjh]

Blackcat,
   You make a good point regarding what I'm hearing from my TT vs. the CDP.  I'll have to make some evaluations regarding that this weekend.  I have some duplication in my music collection on LP and CD.  I'll get 'em both going at the same time and compare.
   
   Last night while listening at conversation levels, I thought the system sounded very good.  I heard more authority from the speakers, more base, nice details etc.  Maybe the "burn in" isn't a myth.  It's been almost a month and the amp has been running consistantly w/ either the tuner or the CDP.  The soundstage has never been 3D, but it's always been like that prior to the Odyssey.  I'm not giving up yet.    
   
   The monster speaker wire might be crap.  I am considering upgrading that.  Regarding that,  the Monster rep I've been emailing says the silver color tint in the wire is from Silver.  "A small amount", he said.  Whatever.    2 bucks a foot.  What can you expect.  There is a big controversy regarding expensive speaker wire.  Is it worth it?  There appears to some benefit to woven wire which reduces the inductance in the wire.  I might look into something like that.  Some of the Kimbers are structured like that.  We'll see...

[BlackCat]

hammergjh:

If you think you'd like the Kimber, and if you have the dexterity, and if you want to save a lot of money, check out the DIY Cat 5 speaker cables.  There are lots of recipes out on the net, but this one looks particularly "Kimberish"

http://www.tnt-audio.com/clinica/triple_t_e.html

Lemme know if you give it a try, I myself write software all day and can't afford the blisters on my fingers.