[Merle]

I recently bought a used Khartago amp from a fellow member. It was advertised as a "9" with original box and manual, with very little use. Upon receiving it, it was none of the above. Cosmeticly, I'd give it a 7, looks like it's been knocked around a bit. It did come in the original box, but without the internal packaging stuff, it was drowning in a sea of styrofoam peanuts, last but not least, no manual or paperwork. I wrote back to the seller, no response. Not a big deal to me as long as it works properly. Now, here's where it gets to be a problem. In the last 2 1/2 to 3 weeks since I got it, I've been dealing with the following:
1. Weird "BOING! sound at turn on. Sounds kind of like a cartoon spring sound.
2. Intermittent humm. Sometimes when I walk down in the basement and it's quite, I can hear humm from the amp. I turn it off, turn it back on [BOING!] and the humm goes away.
3. Upper mid-range and treble sound very good thru this amp. Lower midrange and bass are mediorce at best. Using two pairs of speakers I know to have good, clean bass [Shamrock Keelins & Paradigm Studio 60's] the bass I'm getting in my system is not great. Both my Jolida 502 and 707 have better control in the bass, as well as better all around sound. [I figure that's another story for another time.]
4. I can live with all the above [though I'd rather not] but this next on is driving me nut's. A thumping, spitting sound. It sounds like someone tapping their finger on a needle on a cartridge. This only seems to happen every couple days but it's enough for me that, frankly, I'm a bit concerned about leaving the amp on. The preamp I'm using is a Rogue 66 with brand new tubes and no problems as far as I can tell. [for what it's worth, I've heard the thumping both before and after changing the preamp tubes.
Is it possible I maybe have a prototype that was not meant for the public? Maybe a lemon? The S/N of the amp is 2025. Klaus, is there any history of repairs on this particular S/N? At this point I'd sell it but I don't want to pass it along like it was passed to me. I also cannot afford another amp at this time so I'm pretty much stuck with it. Any suggestions on what I should be looking for? I know this amp should sound and work better than it seems to. Any help?

[Bemopti123]

Send it back to the factory to be checked over.  I doubt that it will be very expensive to fix, for at the price point, it is an affordable amp.  If you are really displeased with the condition of the face plate, I think you might be able to order a new one, of your liking.

[markC]

I think that if you call Klaus and discuss your problem with him, he will solve it for little$. I have delt with the man on more that one occasion and he is all about customer service and upholding his fantastic reputation.

[rosconey]

Labor is inclusive for the first 2 years-

cost of fedex might  be all-
kall krazy klaus   he's INSANE about kustomer service-lol


btw --the boing is a good thing,its the soft start circut

[Matthew Wilson]

Merle Hi, I am really sorry to hear you are having such a nightmare with the the amp.
If you remember I told you i had one for dem and it has the same 'boing' at power-up you describe, although it settles quickly after the relay engages. Some small amount of residual hum is present when compared to the Stratos models and this is symptomatic of a transformer that is less well specified than the Plitron in the Stratos range. My own system has Martin Logans SL3 as the main loudspeaker and it is a viscious load (for any amp) and no mistake! Into this highly reactive load which is down to 1.5ohm the Khartago copes pretty well. The sound quality is excellent across the spectrum as long as I don't push it to far. The bass is taught and nimble and quite fleet of foot but it cannot convey the dynamic scale of the Stratos Mono's into this load. This is not suprising to me at all and by contrast it performs with tremendous control and presence driving dynamic driver spk's such as; Castles' Eden and B&W CDM 1SE (the castle is by far the better speaker incidentally).
The thumping you describe could be many thing's, but sounds like intermitant stray dc thru the system. You need to call upon some buddy's with seperates to track down the offending article. It could be an iffy valve (new or not) or a resistor in either the pre or power. The point is to positively I.D. the culpret by a bit of swop and change. You seem to think it's the Khartago; and from what you've written in the past, you are probably right but I'd get round to a friends with the power amp in the first instance and have a long listen in the context of a compleatly different system.
Hope this helps you move forward. If you find it's definitely the Khartago with a problem call in to Odyssey to speak about service. I'm sure Klaus will sort it out if that is what required. He's just about to go on holiday actually but someone will be there to take the call. Matt

[klaus@odyssey]

Thanks guys,

Yep.  just send it back and we'll take care of it,  giving it a complete "tune-up",  and if necessary,  changing the transformer,  of course.    Not knoing what happened to the amp before, of course,  it nevertheless sounds that something's wrong here,  at least in the ps and the bias.  No matter what,  I'll take care of it. And once the amp leaves here and the thump still exists,  then yes,  take Matts advice because you'll have to look into your system a bit more.
  Call me,

Klaus

[Merle]

Thank you Klaus, I'll call you Monday afternoon.

[Merle]

Thank you Klaus, I'll call you Monday afternoon.

[Merle]

Actually, as I'm not sure this situation is happening because of the amp [it may very well be my preamp, I bought both at the same time] Matt's idea makes since. Is there anyone around Baltimore who would be willing to swap preamps for a couple of days?

[Merle]

I am becoming more and more convinced that the problem I am having is related to my preamp rather than the power amp. I am going to try to find either another amp or preamp to sub in the system to try and isolate where this noise is coming from. I will also screw around with the tubes and wires in the system when I get home from work this evening. I will discover what is going on here and let people know the outcome. I heard from the amp seller. He says he had no such noise problems and I believe him. I have written to the preamp seller to inquire if he had any noise issues. Hopefully, if he did, he will tell me so I can get on with getting the problem fixed. Whichever componet it is, I don't think it's anything serious, I just need to find out which one it is so I can fix it. Wish me luck!