Reconfigured Odyssey Stratos – the Special Fred Edition

drumminman

That's the name Klaus has come up with as it's sort of a one off amp.

This is part review and part update of my amplifier adventure, of which the problems were described here:

http://www.polkaudio.com/forums/showthread.php?146818-Problems-with-Dual-Mono-amp-and-1000VA-A-L-AI-1

Part one: last July, I had Klaus convert my Stereo Stratos with cap upgrade (additional standard grade power supply caps, not the reference ones) to a Dual Mono (with additional transformer and double the caps per channel - still standard grade). It ran hot though the sound quality was much improved over the previous Stereo Stratos. Much more bass slam, better projection of the SDA effect, generally sweeter overall. After about 6 months of use I heard a loud pop one Saturday morning while playing the system at a moderate level. Left channel gone, amp too hot to rest your hand on. So the unit went back to Klaus.

Part two: While he had it in for repair, I had him upgrade most of the power supply caps to reference grade. Couldn’t use those for the four on the upper most board as they’re too tall. To make a long story short when I put the amp back into service it could only be used with my 2.3tl’s without the SDA effect. In other words, no IC cable between the speakers, and no AI-1. We went back and forth trying everything we could think of, but could never get the amp to play well with the SDA speakers. I had to connect the speakers in conventional stereo mode. It still ran hot, but the improvement in SQ with the reference caps was stunning.

Part three: I finally gave up on the Dual Mono because the SDA effect is important to have to really hear what these speakers can do. Back it went to Klaus for the re-conversion. In order to give me the bang for the buck I paid with the Dual Mono conversion for he did more upgrades: the Stereo Stratos now has the black Kismet board, the caps on the board are now reference grade too, plus some other tweaks I can’t think of right now. All of this was at no additional cost.

With only about 30-40 hours of burn in the sound quality is even better than before. I thought I might lose some of the authority of the Dual Mono, but it’s still there along with an even sweeter mid range. Vocal and instrument textures seem a little more enhanced, the sounds seems to emanate from within the room rather than from the speakers.

There’s one fly in the ointment though. I have a horrible grounding problem when the Odyssey Candela Pre is in the system, even when the IC’s are d/c’d from the power amp so that the only thing connected to it are the speakers and the AI-1. It’s a buzz/hum that increases with the volume level.

I’ve tried the following, and nothing helped:

- Cheater Plug on the Stratos to lift the ground
- Cheater Plug on the Candela to lift the ground
- Pulled out the Candela and swapped tubes
- Swapped in shielded IC’s (the ones I use are unshielded)
- Checked continuity on all IC’s
- Plugged the Stratos into an outlet on a different circuit
- Unplugged all other components (DAC, CDP, Subwoofer, Candela Pre) from the wall and d/c’d the IC’s
- Unplugged cable coax and turned off cable box, though the HT is on a separate circuit
- Unplugged cordless phone
- D/c’d the AI-1 so the left and right speakers were only in stereo mode (no IC cable either)
- Made sure all PC’s crossed IC’s at right angles
- Made sure all speaker wires are away from PC’s
- Checked outlets for correct polarity

And here’s what solved the problem:
swapped out the Candela pre from the system and put an older NAD C160 ss pre in its place using all the same IC’s. Voila! An absolutely dead silent background, no hiss-buzz-hum even with your ear on the speaker.

Of course it doesn’t have the beautiful imaging and harmonic richness of the Candela, but at least I’ve narrowed down the problem. Don’t know why I’m having this issue now when I didn’t have it before, but it’s going back to Odyssey for repair.

Love the new Special Fred Edition, even with the NAD :cool:

VR3

My Candela had an extremely loud noise floor fwiw. I just learned to live with it

drumminman

Really? Can you describe it?

Mine had a little bit of a hum before, but it was never loud enough to be annoying. This can be heard across the room and increases with the volume level.

I'm just wondering why it's so much worse now. This is getting to be like playing whack-a-mole!

Glad to have the amp issues worked out though. Even without complete burn in it sounds very good.

VR3

Almost like a low volume version of what it sounds like when you turn your TV to a channel of static. If that makes sense...

SCompRacer

Have you checked the grounding inside the Candela? I had a pre that gave an audible hum in my system. I found they failed to grind the powder coat off the chassis before attaching the ground terminal. It was quiet after I fixed it.

DarqueKnight

SCompRacer wrote: »

Have you checked the grounding inside the Candela? I had a pre that gave an audible hum in my system. I found they failed to grind the powder coat off the chassis before attaching the ground terminal. It was quiet after I fixed it.

If SCR's suggestion about chassis grounding is not the problem, try connecting a grounding wire between one of the amp's case cover screws and one of the preamp's case cover screws.

AsSiMiLaTeD

It seems like I've seen quite a few threads over the year regarding issues with the Odyssey gear, but may be I'm just imagining that. Are the products really that finicky?

VR3

I had one that caught on fire... :-P

audiocr381ve

DarqueKnight wrote: »

If SCR's suggestion about chassis grounding is not the problem, try connecting a grounding wire between one of the amp's case cover screws and one of the preamp's case cover screws.

I have a APC H15 Power Conditioner that has a grounding terminal. If I connected a cable to the chassis of my pre and ground it to the H15 would it have the same effect?

treitz3

Some of you who have posted on this thread may find this link useful. http://www.whatsbestforum.com/showthread.php?9426-Dedicated-lines-and-properly-integrated-grounding-A-discussion

Danny, the only issue I have personally ran across with Odyssey gear is the 3 day warm up with the amplifiers. With the amount of lightning we have here in the Carolinas, along with the 3 day warm up? The amp had to go. I am a patient man when it comes to audio but I am not patient enough to wait 3 days after every time the unit was unplugged due to a lightning storm. Yes it would produce "sound" but the sound and sound stage got progressively worse and it sounded [to me] horrid on day two. On day three, everything came in to fruition and it sounded wonderful [with perhaps a slight mid-bass hump]. Waiting three days for the unit to sound optimal became unacceptable to me.

Tom

Ricardo

AsSiMiLaTeD wrote: »

It seems like I've seen quite a few threads over the year regarding issues with the Odyssey gear, but may be I'm just imagining that. Are the products really that finicky?

This is a common issue with gear from "one man shops".

heiney9

You must be very patient. Not sure I could put up with all these issues for very long without ditching it moving to a more reliable piece of gear.

H9

Ricardo

What time does the APR shop open?????

heiney9

Ricardo wrote: »

What time does the APR shop open?????

8AM and they are only 55 miles away............but first I need to mow and clean out the gutters. Probably not going to happen today.......but it's on my radar. Still reading up.

Although this has me almost convinced.

http://www.automobilemag.com/features/0712_2007_volkswagen_mkv_gti_2008_r32_comparison/

Ricardo

heiney9 wrote: »

Although this has me almost convinced.

http://www.automobilemag.com/features/0712_2007_volkswagen_mkv_gti_2008_r32_comparison/

Almost??? Don't over think it. You'll love it. And forget about people saying 1st gear is worthless......seems they think the gas pedal is just on-off. You'll learn to modulate it and you'll be able to launch VERY quickly without much spinning.

The best part is that your gas mileage will improve between 1-2 MPG.... unless you constantly floor it ....

Oh, and highway speeds are where you'll notice the best improvement; in my manual I rarely downshifted from 6th and could go from 60 to 80 in a bliss. Unless I was really in a hurry.....then 3d gear was my choice and no one could get any close :cool:

drumminman

VR3 wrote: »

Almost like a low volume version of what it sounds like when you turn your TV to a channel of static. If that makes sense...

Yes, that's it, but with a little more low end.

SCompRacer wrote: »

Have you checked the grounding inside the Candela? I had a pre that gave an audible hum in my system. I found they failed to grind the powder coat off the chassis before attaching the ground terminal. It was quiet after I fixed it.

I noticed that it doesn't appear that they ground off the powder coat - good suggestion. I'll try this and report back.

DarqueKnight wrote: »

If SCR's suggestion about chassis grounding is not the problem, try connecting a grounding wire between one of the amp's case cover screws and one of the preamp's case cover screws.

This is also on the list of things for me to try.

Thanks for the suggestions!

drumminman

Problem Fixed! :biggrin:

I've been listening to the rig with the NAD pre for the last week. I had forgotten what a nice little unit it is, and at 1/3the cost (bought used) of the Candela. Very good soundstage, but lacking the clarity and harmonic richness of the latter.

Earlier in the week I put in a call to Alex, the designer of the C, and we had a nice long chat. He gave me 5-6 options to try. At the end I suggested running a wire connecting the chassis of the C to the Stratos. He agreed that could work.

This am I checked the ground connection on the C (the powder coat had been ground off during production - wouldn't have checked without the tip from SCR) ran the wire, put the C back in the system and powered up. A very slight hum that could only be heard with my ear on the speaker. And it did not increase with volume level. No other changes made. Such a simple fix for an unbearable problem.

Willie N. making sweet music as I type this, all is well with the big rig, the AI-1 is in the system, full SDA effect happening. Only thing I need to do now is swap in the Amperex 7316's for the RCA clear tops.

Thanks to everyone who helped with suggestions. And DK, once again you were on the money.

SCompRacer

drumminman wrote: »

Problem Fixed! :biggrin:

Kewl! Good work! DarqueKnight scores again! You can experience wierd ground loops from having different length power cords too.

I am obsessed with having the lowest noise floor possible. When I hear hums from speakers, I have a habit of touching gear and using myself to ground it, which can get you a shock if something is shorted. That is how I found the ground problem I described above. By touching the pre and another piece of grounded gear the hum subsided. I'm a hands on kind of guy....lol

drumminman

SCompRacer wrote: »

When I hear hums from speakers, I have a habit of touching gear and using myself to ground it, which can get you a shock if something is shorted. That is how I found the ground problem I described above. By touching the pre and another piece of grounded gear the hum subsided. I'm a hands on kind of guy....lol

Never thought of doing that. I'll have to file it away under "trouble shooting techniques"!

DarqueKnight

drumminman wrote: »

Problem Fixed! :biggrin:

This am I checked the ground connection on the C (the powder coat had been ground off during production - wouldn't have checked without the tip from SCR) ran the wire, put the C back in the system and powered up. A very slight hum that could only be heard with my ear on the speaker. And it did not increase with volume level. No other changes made. Such a simple fix for an unbearable problem.

I'm glad you got some relief. You might be able to reduce or eliminate the residual hum by running ground wires from the preamp case to each source component case. Larger gauge wires might also help.

drumminman

DarqueKnight wrote: »

I'm glad you got some relief. You might be able to reduce or eliminate the residual hum by running ground wires from the preamp case to each source component case. Larger gauge wires might also help.

Next on the list. I've never not had a slight bit of hum so eliminating it entirely would be great.

One thing I've noticed is that the SQ is so much better with the hum reduced to the present level. I thought I could only hear it with music playing during quiet passages, but it seemed to impart an overall slight grunge. It was only noticeable when it disappeared. Don't think it's my imagination.