Transaudio T9.4 not compatible with Cary SLP90...

[Mordor]

A few ago i notice some sporadic pops or cracks, from left speaker.

I contact the seller of the amp Transaudio T9.4 speaker, and for my surprise, i highly advice me not to use this combination:

"Hi Jose Good day We appreciate your positive feedback. We observed that you are using the valve preamp with the T9.4 amplifier. Due to the high sensitivity of the T9.4 circuit, the voltage generated by the valves during operation can:
Prevent prematurely activate the protection system
Cause unprogrammed shutdowns Our engineering team formally recommends:
Avoid combination with thermoionic preamplifiers These configurations generate voltage variations incompatible with the T9 solid stage architecture4. We thank you for understanding technical specifications. best rings k"

I already resolve the problem of the pops, but this incompatible, now, gonna probably make me sell the Cary and go for a 2860 Plus......
Already gonna conect the DAC directly to the T9.4, and avoid the Cary SLP90 Clone.

IM sad, because i real like the sound of the Cary, and already was thinking make some improvements to the electronic and tubes.

Can someone with better electronic or equivalent system explain better this "incompatibility"?

I apreciate real help.

Jose

 

[DVDdoug]

Due to the high sensitivity of the T9.4 circuit, the voltage generated by the valves during operation can:

I assume there is a volume control somewhere? You can also get attenuators.

High sensitivity makes everything "louder", including any noise. But it doesn't create clicks & pops.

pops or cracks, from left speaker.

You can swap the left & right connections to determine where the noise is coming from.

Can someone with better electronic or equivalent system explain better this "incompatibility"?

I don't know what they are trying to say...

I don't know about this equipment but generally, Line level is line level, whether from tubes or solid state. However, there are different pro and consumer standards, it's never "calibrated" in home equipment/setups so it varies, and there is often a volume control.

and tubes.

Tubes are way-outdated and dumb! You can make a good amp with tubes but it's more expensive than solid state and less energy efficient.

 

[Mordor]

Thank you so much.

A friend of mine with same set up also actually buy a atenuator.

Clips and pops were due bad contact on amp, where there is a small switch to change betwheen RCA and XLT inputs. A little on//off did the trick

I like the tubes sound or "distortion" ans some call it. The Cary doesnt introduce and kind of distortion. Is only a Pre and not a amp. For amp i think is better solid state.

Funny fact, on level 5 volume on Cary, it still plays loud....and not too much difference from 5 to 15.....

 

[MaxwellsEq]

As an electronic engineer, I can't say I understand what they are claiming:

Due to the high sensitivity of the T9.4 circuit

The way I interpret this is that the power amplifier achieves full output with relatively low line-level voltages. This wouldn't necessarily mean tube preamplifiers are a bad match: any preamplifier with lots of gain and high maximum line-level voltages would potentially be unsuitability.

As an observation - they ought to design the power amplifier with switchable gain and design its front end to not be easily overloaded.

the voltage generated by the valves during operation can:

Again this doesn't necessarily make sense. A solid state preamplifier with high line-level voltage swings could overload the power amplifier's input stage. As before, perhaps the power amplifier could be better designed to not easily suffer overload.

Sure, tube gain stages operate at much higher voltages than solid state, but (unless broken) those voltages are not exposed at the line-level output.

 

[Mordor]

Im not engineer, but the seller higly advise me NOT use T9.4 with Cary, but instead, Accuphase 2860 Plus clone, for example, that doesnt use tubes.

For now, im gonna bypass the Cary, and connect the DAC directly to the amp T9.4.

So far, everything is working flawless with Cary conected.

One strange thing i notice from beginning: even at 1 volume, the Cary give a strong high volume, and there isn`t much difference between volume 5 and 15...( 0-99 scale)

Thank you for feedback here.

 

[MaxwellsEq]

Im not engineer, but the seller higly advise me NOT use T9.4 with Cary,

I am an engineer, as this advice is not based on clear logic.

One strange thing i notice from beginning: even at 1 volume, the Cary give a strong high volume,

They did explain that to you. Their circuit probably has insufficient overload margin and has sensitivity that is designed for preamplifiers with low voltage line outputs. It's nothing to do with a tube preamplifier.

Personally, I'd return the power amplifier.

 

[mhardy6647]

Perhaps the concern is DC riding on the Cary's output and potentially wreaking havoc with the "Transaudio T9.4"? (I don't know what a "Transaudio T9.4" is, sorry!).

Especially since vintage vacuum tube sources are (were) notorious for DC offsets riding on their outputs... utterly benign in classical vacuum tube audio amplifier circuits, which always had capacitors, chokes, and or transformers between input and loudspeaker outputs.
Conversely, feeding, say, a few hundred millivolts of DC into the input of, e.g., a fully direct-coupled, wide bandwidth, high gain solid state audio power amplifier could (can!) cook a loudspeaker pretty efficiently (and distressingly quickly).

 

[Mordor]

This is a Transaudio T9.4:

Also reviewed by a engineer.
The poweramp drives very well and i don`t see any distortion or any kind of problems with my Dali. In fact they are becaming better with time even a high volumes. Them amp sure controls them quite well.

Question: like above stated, can i use a attenuator on output of the Cary?

 

[MaxwellsEq]

(I don't know what a "Transaudio T9.4" is, sorry!).

It's a clone. It has low input sensitivity.

 

[mhardy6647]

"Burmester". oy vey.

I'm gonna stick with my in silico diagnosis: DC.
Nothin' an input capacitor (or transformer) won't fix.
I doubt that an attenuator will, though -- unless it's a TVC or an AVC

 

[Mordor]

Thank you guys.
Just in case gonna re-conect the T9.4 directly to the dac and avoid the Cary for now. I was thinking make some updates on Mosfets and tubes, but is a lost cause now.

Gonna start getting money for a Accuphase "clone".....................