[Eric H]

It's been a few weeks without news...  did you get your clarinet working?  What's the status?  I hope you didn't give up - what you're trying to do should work, I think, but sometimes custom jobs can be tricky to debug...

[RODA]

Hello

I don't hva any GOOD news, but here goes:

- As I said, I tried to shorten the inputs. This didn't help lowering the noise at all. (I have bypassed the DC-blocking capacitors since my source have no DC-offset.

- I dont have grouded electricity in my listeningroom, so noise from the supply-current cannot be a problem.

- My rca interconnects between pre and amp are DIY, made from twisted copper-cables. Once i tried a pair of coax rca-cables.....WOW!    The noise was considerably lowered, and went from "angry" hizz to "nice" noise.

How can my rca-cables affect the noise so considerably?

I now believe that the noise is caused mostly because of the mismatch in gain. How can i lower the gain out from the Clarinet by aprox. 5-10dB?
Resistors in series an paralell, but which values?

Someone tipped me that I should try ceramic capasitors of 0,1 microfahrrad in paralell with the inputs and outputs to eliminate highfrequency problems with the circuit.
Does that make avy sense?

[hagtech]

There is no easy way to reduce gain, without really screwing up things.  Tube was chosen for it's low mu.  Sure, you could add an output pad, but that does nothing but increase distortion and output impedance.

No high frequency problems with this circuit.  I would not add ceramic caps anywhere!  The CLARINET has proven in many installations to be supremely quiet, robust, and oscillation-free.  If you are having any of these problems, it is probably a system issue.  Best to address the true cause, rather than trying to hide symptoms with band aids.

Not having a ground can be a bad thing, not good.  You need to reference the system to something, so it is not floating and prone to pickup from interfering sources.  I think the improvement using shielded cables is indicative of this.  

jh

[RODA]

No high frequency problems with this circuit.  I would not add ceramic caps anywhere!  The CLARINET has proven in many installations to be supremely quiet, robust, and oscillation-free.  If you are having any of these problems, it is probably a system issue.  Best to address the true cause

OK. Thank you Jim.

I also believed that introducing the ceramic caps would be the wrong way to go.
My next step will be to change the internal wiring to a shielded type, and follow the others tips you gave me earlier in this tread.

The gain have to stay as is. I don't want to do any modifications that will give a poorer performance from the CLARINET.

But first of all I'll have to bring it to my friends system, just to check if the noise comes from a poor "co-operation" with my power-amp.

I will keep you posted, hopefully this will be helpful for others doing changes to the original CLARINET.

What about me removing the first two capasitors?
OK when my source have no DC-offset?

BR
Rolf

[RODA]

Small update:

- Buzz
Have discovered (by trying other tube-preamps) that the buzz really isn't loud at all. I was previously used to solid-state.......

- Hum
This is a bit of  a problem.
Will try to move the tranny outside of the cabinet.

- Sound
     
I have borrowed a friends Audible Illusions Modulus M3A.
The AI is a bit heavier in the bass (Amperex Bugleboy), but the Clarinet is a killer in soundstage and "airy" sound.
A lot of details in the sound from the Clarinet!!
I am very pleased!!  

[RODA]

After listening for a longer time, I (of course) came to the conclusion that the Audible Illusions is far better than the Clarinet.
What put me off in the start was that the Clarinet lacks "weight" at thereby sounds more detailed.

BUT:

Now I am pleased with the sound from my system!!!
Reason: I bought a new preamp  

It's a real bargain, and costs just about nothing.
Strongly recommended!!!

The preamp is MING DA MC-7R  
I changed the tubes from the original "crap" and WOW!!  
Of course this is not the case for some of you, but for me this is a far better sounding preamp.

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