Need help - black out while the amp. was on

[Megaudio]

Originally Posted by Conrad Hoffman

Tube amps are in fact extremely robust. Either you have a problem that a competent tech should be able to locate quite quickly, or more likely you've been burned once and have sufficient paranoia that the amp can't sound right. The only way to fix that is do a blind comparison with some amp you regard highly. We're all subject to FUD (fear, uncertainty & doubt) and the results on our perception are very real. BTW, where are you?

Hi Conrad....I know all that and believe me..I am not paranoic..the amp. I am speaking about is CAYIN A 100 T....this is monster amp and it sounds like monster..heavy,deep bass as by SS..realy hiend amp...but now sounding like..let's say..amp for about 1000$...hope You have perception what I am speaking about...this terrific bass is just not there any more...now imagine You have bass control on the amp and take some 2-3 DB minus..so this is the effect I hear...and the highs are more present..of cousre I could listen the amp like that but that's why I bought this amp..because of his great bass and now it's gone...by the way I am from Croatia...small country near Italy

[DF96]

Has your "guru" checked the OPTs? Measure the primary inductance - this will show up shorted turns.

[Conrad Hoffman]

Definitely do the measurements on the amp, but check the speakers too. Could there have been some spike that damaged a driver or crossover? Anything that affects the frequency balance could give the effect you describe.

Another thing to look at is the current draw of the amp and the temperature of the transformers. If there's a shorted turn I'd expect the power consumption to go up, especially if it's in the power transformer. It would run warmer than normal. The problem is that if the change is subtle, it will be hard to tell without prior data on what's normal for the amp.

[Megaudio]

Thank You for so much help..thanks..I appreciate that...but..I sold the Cayin and already have new monster but this time and 500 w UPS perfect sinus,double conversion....now the amp. is always conected on battery..no more black outs..this is special UPS for HI FI equipement giving no break power of 220 v + - 2%...so...now to the amp...MING DA MC-34-AB...out of the box..sound is FANTASTIC..SUCH TREMNDOUS,dinamic stage and space,such live feeling..realy happy about it....2 6SN7 Onion shape are realy much better then Electro Harmonix 6sn7 ...only input 12AT7 I will put there Tung-sol for the begining...but I realize that my speakers which are 4 ohm sound much,much better conected on 8 ohm port of the amp...how 's that possible????...another question...which 12AT7 would be the best deal for this amp?