Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...

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Chops

Re: Khartago Kismet amps and Allen Wrenches...
« Reply #20 on: 21 Oct 2015, 05:38 pm »
Okay, so after messing around with the offset some more, I managed to get it centered around 00.2 - 00.6 mV, but it still swings roughly 1 mV in either direction. And this was with an hour's worth of fiddling and monitoring.

As for bias, I set it a little higher than the recommended 21 mV. I have it set to 22.6 mV, which for my current speakers seems to be ideal. With the slightly warmer bias, it tends to balance out the speakers quite well. Let's hope the settings stay this time and not drift way up again.







« Last Edit: 21 Oct 2015, 08:45 pm by Chops »

thirdeye

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #21 on: 21 Oct 2015, 08:15 pm »
From your photos not sure if that is a terrible factory solder or not on those clear brown speaker cables to the board? I assume they are the cables feeding the extra capacitor banks on the sides from what it looks like?

In any case another observation of your setup from the photos is you are running that amp into a really generic APC power conditioner. I actually own the same exact one, but pulled it from the audio duties in the main system. It's okay for front end gear, but it has a small transformer, and your amp should be directly into the wall which could be a part of your "Floating" measurements issue. By the way very few if not ZERO power conditioners on the market will benefit any amplifiers without seemingly making them sound more congested in general. And the APC from first hand experience will do just that.

I will say back when I had the Stratos Extreme mono amps I was always having to fiddle the bias on those amps. They never totally worked out tonally for me. They are decent amps for the money, but I have found some odyssey designs may or may not ultimately be the most musical with all associated gear, and speakers.

A big reason I think they always seemed a bit forward, and thin sounding was that these amps simply have VERY low input impedance for most preamps to drive... They are only like 10,000 ohm or something [same as most subwoofer plate amps I have used] which matched with a standard 600 to 1500 ohm type preamp can really roll off the bass pretty early. I like amps with minimum 20,000 ohm input, and most really good amps I have owned were 50,000 to 100,000 ohm inputs universal with just about any source or preamp you feed them getting that full feeling smooth frequency bandwidth. You gotta run a really low output impedance preamp in my opinion with this amp like a 50 to 200 ohm sweet sounding Conrad Johnson tube pre or something if you want to knock out some of that "German solid state" sound these might exhibit from my experience.

Chops

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #22 on: 21 Oct 2015, 08:43 pm »
From your photos not sure if that is a terrible factory solder or not on those clear brown speaker cables to the board? I assume they are the cables feeding the extra capacitor banks on the sides from what it looks like?

In any case another observation of your setup from the photos is you are running that amp into a really generic APC power conditioner. I actually own the same exact one, but pulled it from the audio duties in the main system. It's okay for front end gear, but it has a small transformer, and your amp should be directly into the wall which could be a part of your "Floating" measurements issue. By the way very few if not ZERO power conditioners on the market will benefit any amplifiers without seemingly making them sound more congested in general. And the APC from first hand experience will do just that.

I will say back when I had the Stratos Extreme mono amps I was always having to fiddle the bias on those amps. They never totally worked out tonally for me. They are decent amps for the money, but I have found some odyssey designs may or may not ultimately be the most musical with all associated gear, and speakers.

A big reason I think they always seemed a bit forward, and thin sounding was that these amps simply have VERY low input impedance for most preamps to drive... They are only like 10,000 ohm or something which matched with a standard 600 to 1500 ohm type preamp really rolls off the bass pretty early. I like amps with minimum 20,000 ohm input, and most really good amps I have owned were 50,000 to 100,000 ohm inputs universal with just about any source or preamp you feed them getting full feeling frequency bandwidth. You gotta run a really low output impedance preamp like a 50 to 200 ohm sweet sounding Conrad Johnson or something if you want to knock out some of that "German solid state" sound these might exhibit.

Those brown cables are just for the LED lighting on the front panel. The extra capacitors are wired in under the board.

As for your specs on these amps, you're way off. The input impedance on these amps are 22k ohms, just like most other amps on the market. The output impedance of my McIntosh preamp is 600 ohms, again, like most other preamps on the market. This amp is definitely NOT forward or lacking in bass. Those are two areas that Odyssey amps are known to excel in in fact. Pretty much, everything you've said in your post is the exact opposite of the truth.

Also, that "really generic APC power conditioner" as you call it is actually known to be quite good considering its price point. I have seen that very unit used in systems much costlier than some new cars, hence why I went with it to begin with. It also helps maintain a constant output voltage, so it wouldn't be the cause of "floating measurements".

thirdeye

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #23 on: 21 Oct 2015, 08:49 pm »
I may have been off on this amp if the newer ones have changed input impedance, however the older Odysseys all had a 10k inputs trust me.

My point still remains I would take it off the power conditioner. It is not a re-generator as you claim, it is simply a fancy LED volt meter display which will indicate if you have a large voltage drop or spike, and lets you see the current voltage from your wall. So it is not stabilizing any voltage, its just conditioning whatever is there... Again it is not a re-generator. The APC will not step up or step down voltage and hold to a perfect 117 volts.

I was not trying to ruffle feathers here, but go ahead and check with Klaus on this I can pretty much guarantee he will agree to take it off, and go straight to the wall. By the way the transformer in the APC is much smaller VA than the big Toroid VA in your amp so again I would not use it, and go from there.

And to further the reality about AC it would be great if we all had EXACTLY 117 volts from our wall which 99% of any gear is based off. They build these amps in a controlled type AC unit feeding it perfect voltage. However, I would not doubt the APC is reading 121 to 128 volts because most of the U.S. sent to the house is very high in most parts of the country which makes a lot of audio gear sound "Sterile" which is exactly why you have done the right thing to BIAS the amp to get back the missing current being the wall. 

Some amps now have better more sophisticated auto biasing systems which compensate for this, the Odyssey does not it is manual, and of course any power amp the cost comes from how well regulated the power supply is which is why we have 1500.00 amps, and 50,000 dollar amps in the market. This is why the bias will be out of whack compared to controlled conditions, and exactly why Klaus allows people to adjust their amps in home not voiding the warranty.

None of this is a bash against Odyssey every piece of gear will not necessarily run optimally at all times with our uncontrolled house AC systems which is why many go to great lengths, and costs getting the dedicated lines, and whole system voltage regulation put in when they go with very serious equipment.

Good luck

Chops

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #24 on: 21 Oct 2015, 09:41 pm »
Regardless of the amp being connected to the APC, that's a non-issue for me. Living in an apartment, I never push this amp to its full capabilities. My speakers are rated at 91 dB @ 1 watt and I highly doubt the amp ever gets out of Class A. It just sits there idling most of the time.

I never said anything about power regeneration. The APC H15 has a Boost/Trim feature that I have set to "Narrow". So if the voltage at the wall varies between 114 - 126 V (5% from 120 V), the H15 regulates the output voltage back to 120 V. It's never gone into Trim mode, but I did witness it going into Boost mode a couple times last winter for a brief moment.

thirdeye

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #25 on: 21 Oct 2015, 09:46 pm »
Understood, however pushing the amp is not the important part... It will perform better at LOW volumes being fuller, and more transparent because you are opening up the power supply balancing the current to the amp vs. down choking it thru a much smaller transformer than is even in the amp itself.

Again I have no beef with your decision, just trying to help you get optimal performance because its always good to get your moneys worth correct?

Beyond that you can find many opinions in Audio Forum posts most pointing toward almost everyone goes thru the power conditioning stage, which can work well on all gear, BUT the bigger power amps, and almost everyone finally ends up going direct to the wall with amps for better results.

Chops

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #26 on: 21 Oct 2015, 10:27 pm »
Well, I also live in central Florida, lightning capital of the world. We get thunderstorms all times of the year, not just summer, so there's no chance of me plugging equipment directly into the wall without protection.

JackD

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Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #27 on: 21 Oct 2015, 11:40 pm »
Chops

Try one of these.  This is what I use so I can plug the Kismet straight into the wall where it does sound better. This protects every outlet on a particular breaker.  I live North of you in the Panhandle so more than familiar with the lightning and surge situation.  I have one plugged into an outlet of every circuit that AV equipment is on.  I order them in packs of three from Walt at TLP.  They are cheaper that way and I have spares.

http://www.bluecircle.com/page95.html

Jack

klaus@odyssey

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #28 on: 22 Oct 2015, 02:17 am »
a few comments:

- Whenever biasing an amp,  it has to be on for at least 2-3 days to make sure that the ps is completely charged
- auto bias would be nice...if prices could be held in check, and if it wouldn't interfere with sq
- yes, it is impossible to stick at 0.00 mV pretty much with any amp...the fluctuations you see are mostly due to fluctuations in your AC
- with the offset, anything under 5-10 mV is acceptable...not as good as close to 0, but you wouldn't be able to hear the difference.
- yes, it is true that the AC average in the US used to be 119.6 V 10 years ago, via one Energy study.  However, as nearly 100 % of my customers across the country measure their AC so that I can nail down the bias for them individually,  I pretty much see 121.5  - 122 V as the median these days...of course not the same for winter or summer...
- yes, it used to be 10 K,  but we have changed to 22K years ago.............
-  man oh man,  it takes a lot to make any of our amps sound thin, especially when somebody rebiases them...and especially on the Extremes...just shows you that some  associated equipment will indeed stamp its own signature on the sound,,,again, synergy, synergy...there is no silver bullet.

Lastly, as for the German solid state sound....ok, the first couple of years in the late 90's and early 2000's  we pretty much duplicated the design,  but over the years I personally tweaked and optimized the shit out of them, making them extremely realistic and a bit on the full, rich, and warm side.....took me years to be where I am now.  But it is nice to know that our amps are decent for the money though.....

Late,
Klaus

GentleBender

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #29 on: 22 Oct 2015, 02:24 am »
Well, I also live in central Florida, lightning capital of the world. We get thunderstorms all times of the year, not just summer, so there's no chance of me plugging equipment directly into the wall without protection.
You can't be too far from me in Ocala, Fl. I have trusted God and have just unplugged everything if I thought a storm was coming. Not the smartest thing I've done, but it sounds so good and lightning is tough to beat. I have to say there have been times at work that I was really worried about what I was coming home to.  :o

Chops

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #30 on: 22 Oct 2015, 02:41 am »
a few comments:

- Whenever biasing an amp,  it has to be on for at least 2-3 days to make sure that the ps is completely charged
- auto bias would be nice...if prices could be held in check, and if it wouldn't interfere with sq
- yes, it is impossible to stick at 0.00 mV pretty much with any amp...the fluctuations you see are mostly due to fluctuations in your AC
- with the offset, anything under 5-10 mV is acceptable...not as good as close to 0, but you wouldn't be able to hear the difference.
- yes, it is true that the AC average in the US used to be 119.6 V 10 years ago, via one Energy study.  However, as nearly 100 % of my customers across the country measure their AC so that I can nail down the bias for them individually,  I pretty much see 121.5  - 122 V as the median these days...of course not the same for winter or summer...
- yes, it used to be 10 K,  but we have changed to 22K years ago.............
-  man oh man,  it takes a lot to make any of our amps sound thin, especially when somebody rebiases them...and especially on the Extremes...just shows you that some  associated equipment will indeed stamp its own signature on the sound,,,again, synergy, synergy...there is no silver bullet.

Lastly, as for the German solid state sound....ok, the first couple of years in the late 90's and early 2000's  we pretty much duplicated the design,  but over the years I personally tweaked and optimized the shit out of them, making them extremely realistic and a bit on the full, rich, and warm side.....took me years to be where I am now.  But it is nice to know that our amps are decent for the money though.....

Late,
Klaus

Hello Klaus,

Just to make things clear, I have zero complaints with my amp. I realize the offset bounces around due to the line voltage, but wasn't sure how drastic the offset swings were supposed to be to be considered normal. Now I know, so I'm not too concerned about it. I assume dipping to -01.3 mV is alright.

So far, I have heard this amp on three totally different systems in two different homes, controlled by either three different AV receivers and four different preamps. Not once did this amp ever sound thin or lack bass. Never.

On a side note, I ordered another PS Audio Power Port so I can install it on the other side of the system and plug the APC into it, then I'll plug the Kismet into the existing Power Port along with one of those Blue Circle Yalu Bulala that Jack informed me about. See if that makes any difference. From what people say, it should, even at low power levels.

JackD

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Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #31 on: 22 Oct 2015, 02:52 am »
My first Odyssey amp in 1999 was a "dealer floor model" from the days that Klaus sold through dealers.  If I remember correctly it and the Mono's I had a couple of years later were both 10k, but as Klaus said that changed to the current standard of 22K pretty quickly.  From the first Stratos to the current Kismet thin is not something I would use to describe an Odyssey amp. They are the industry standard for what is capable at a fair price.  If I remember the review correctly, Jonathan Valin of AS said they were 90% of the $70K Solution amps for a 20th of the price.  If you can't get an Odyssey amp to sound good you are doing something wrong.  Same goes for the speakers.

Chops

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #32 on: 28 Oct 2015, 11:30 pm »
I have a couple things to say...

First off, I stand corrected. Thirdeye is correct in saying that the amp will probably sound better being plugged directly into the wall, even at lower volumes. He said "It will perform better at LOW volumes being fuller, and more transparent". This is exactly what I witnessed today when I plugged my amp directly into the wall outlet. The surprising thing is, it isn't a subtle improvement. It's pretty drastic!

One thing for sure, since using these X-Statik speakers again, I boosted the bass on the McIntosh preamp just a touch to help add in a little "oomph". Well, after plugging the amp into the wall, I had too much bass, and so put the bass back to flat. Beyond that, the bass is not only stronger and tighter, but also extends a little deeper now, really making these speakers sing. A couple of other things noticed is that the sound stage has opened up a little more, and there's tons more dynamics now. It's very lively and snappy. Detail has been improved as well, digging even deeper into the heart of the music, grabbing all of those textures and bringing them out to enjoy. I really wasn't expecting any of this. It's definitely an eye opener for sure!

As for any kind of ac line noise getting into the amp from no longer being filtered, I first disconnected the inputs and turned the amp on. There's just the very slightest bit of hiss when you have your ears plastered up to the tweeters. No more or no less than when connected through the APC. Apparently, the amp has excellent filtering on its own.

That doesn't mean I'm going to leave it unfiltered though. I'm not. I'm in the process of figuring out which way to go first with the Blue Circle Audio products. There's several different things I can go with, all of which can be added to one another to improve filtering even more. It's just a matter of choosing which one to go with first. Choices, choices...


Jack... I ordered one Yalo Bulala last week which I told you about. I'm still waiting for it to show up in the mail. Looks like it should be here tomorrow. I'll be installing it in the bedroom adjacent to the family room where the system is since some of the outlets in that room and this one share the same circuit. That will put it closer to the break box also, which probably helps.

JackD

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Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #33 on: 28 Oct 2015, 11:48 pm »
Charles

I am using two of the FX2 models.

http://www.bluecircle.com/page151.html

Another option is the miniBuss, though I don't know about the lead time on them. They are different takes on the same idea.

bunky

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #34 on: 28 Oct 2015, 11:52 pm »
I run a MIT Z duplex power outlet that uses three tuned parallel filters. the Z duplex does not restrain the dynamics of a power amplifier.

Chops

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #35 on: 28 Oct 2015, 11:59 pm »
Jack... I'm not too sure what the miniBuss is. Nothing seems to show up via Google other than vans and buses. LOL

bunky... I've already invested in a couple of PS Audio Power Ports, one of which I installed a few months ago, the other I just installed a few days ago. Plus these electrical boxes in this apartment are tiny. I doubt the MIT Z outlets would even fit in these boxes with that added little box on the back of them.

Plus, I really like the concept and design of the BC PLC's and other items. I'd rather go with them for all of my filtering needs.

JackD

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Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #36 on: 29 Oct 2015, 12:53 am »
PI Audio.  They had a Circle here for years until recently. Look just below the Odyssey Circle.

http://www.piaudiogroup.com/MiniBUSS.html

Gilbert's are cheaper due to the "Unique" casing and you can chose outlet numbers.  They work for me.

Chops

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #37 on: 29 Oct 2015, 01:19 am »
PI Audio.  They had a Circle here for years until recently. Look just below the Odyssey Circle.

http://www.piaudiogroup.com/MiniBUSS.html

Gilbert's are cheaper due to the "Unique" casing and you can chose outlet numbers.  They work for me.

Ah, okay. Thanks for the clarification.

mresseguie

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Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #38 on: 29 Oct 2015, 01:41 am »
Hi, Chops.

I just noticed this thread. I see you're seeking some sort of power conditioning for your system, and I noticed the reference to the PI Audio MiniBUSS, so I thought I'd bump my head in.

I don't own a Blue Circle product myself, but I hear great things about them. I also don't have the MiniBUSS myself (though I visited AC member 'Captainhemo' who has one in his system). However, I do have a PI Audio UberBUSS in my system, and I love it. There used to be more hiss in my system than I cared for, but once I hooked up the UberBUSS, all (yes, ALL) hiss was gone. That was two years ago, and I've never looked back. The $1095 (I think) price is about half what PS Audio charges for a similar unit.

So I suppose I've become an UberBUSS fanboy. It is a cool sounding name to boot.

Best of luck in your search!

Michael




AlTran

Re: Khartago Kismet amps and Allen Wrenches, DC Offset & Bias...
« Reply #39 on: 29 Oct 2015, 06:09 am »
Dear all,
I plug my Thorens 124, symphonic line klarheit, odyssey Suspiro se, candela into my Blue Circle GICPO and also added a Blue Circle X0E module. I plug odyssey kismets mono blocks into my Blue Circle PLC FX2 X0E. By far the best results I've heard in any systems regardless of price. DEAD DEAD DEAD QUIET, BLACK BLACK BLACK BACKGROUND, during the music is playing and if there is a mosquito flies by, I'm sure you will hear it flies by. I've tried quite a few others conditioners but so far none is better the results I currently have at this time.