Klark Teknik KT-2A

[living sounds]

I did change the tubes for selected Tung-Sol ones in both the KT EQ and tube compressor (where availible, otherwise selected Tube Amp Doctor tubes) and found the sound to be cleaner, less gritty, more precise with better bass and less dynamic constriction while retaining the pleasant transformer coloration.

Here's a comparison I did a couple years ago with the EQ:

http://www.dropbox.com/s/d35tan0nu548ns0/BehringerTubes.wav?dl=1
http://www.dropbox.com/s/im752rl9yc5zd9k/NewTubes.wav?dl=1

 

[[email protected]]

Thanks for the advice. How difficult is it to change the yellow capacitor?

It's really easy if you know how to use a soldering Iron.

Did you notice any difference in noise with the changed T4b, Mundorf capacitor and upgraded tubes?
For me, yes.The sound is more precise and detailled. But the compression is also most important. i Can turn completely the Peak reduction knob and having no saturation.

 

[FarisElek]

Does your unit has a notice able noise floor? I never once noticed a bad noise floor before or after modifications. I’d say the unit is one of the cleanest units I’ve ever owned. You may have something faulty.

 

[dickiefunk]

Thanks for the replies guys. I wouldn’t say the KT-2a is noisy under normal operating levels at all.  It’s only when I crank the output when tracking but that’s probably down to gain staging etc.

I have the KT-2a, 76-KT and EQP-KT and all of these have pretty low noise unless you start really cranking the output!

 

[FarisElek]

I've never had to move the output farther than it sitting with the potentiometer pointing straight left.  It's actually bothered me at how little gain I need, because I've wanted to impose more tube signal. You're tracking too softly. 

Ryan

 

[dickiefunk]

I've never had to move the output farther than it sitting with the potentiometer pointing straight left.  It's actually bothered me at how little gain I need, because I've wanted to impose more tube signal. You're tracking too softly. 

Ryan

Hi Ryan,

Thanks yes I agree, you really don’t need to use a lot of output whilst tracking 

I suspected that when I turned the output up higher, I was messing up the gain staging!

 

[doggy6812]

I am wanting to change out the transformers on the KT2a. Does anyone know  what ratios these output and input trannys are?

 

[FarisElek]

I'm not sure what it is but you can find the DC resistance of them to find out. I'm sure you can find info on measuring DC resistance somewhere here or somewhere else on the net. Good luck and let us know if you find a suitable replacement for them. I'd imagine the input would be more important for adding color to the signal.


Ryan

 

[Whoops]

I am wanting to change out the transformers on the KT2a. Does anyone know  what ratios these output and input trannys are?

I totally respect your wish, but just to let you and everyone know that the stock transformers are quite good.

Regards

 

[Rob Flinn]

I'm not sure what it is but you can find the DC resistance of them to find out. I'm sure you can find info on measuring DC resistance somewhere here or somewhere else on the net. Good luck and let us know if you find a suitable replacement for them. I'd imagine the input would be more important for adding color to the signal.
Ryan

d.c resistance will not help you know the ratio or impedance of the transformer.  It is purely the resistance of the wire being used.

 

[FarisElek]

d.c resistance will not help you know the ratio or impedance of the transformer.  It is purely the resistance of the wire being used.

Oops. A transformer manufacturer recently asked me for the DC resistance of a transformer when I asked if they had a suitable replacement for a transformer I had no info on.. I’m not sure why they asked. I just assumed it was to find the turns ratio. But after looking into it I see that you’re right. Sorry about the wrong information, everyone.

 

[abbey road d enfer]

d.c resistance will not help you know the ratio or impedance of the transformer.  It is purely the resistance of the wire being used.

Measuring DCR is not entirely a waste of time.

• Knowing the DCR gives a rough estimate of the nominal impedance. Decent manufacturers make sure the DCR is about 1/10th of nominal impedance.
• Seeing equal DCR at the pri and sec is a good indicator of 1:1 ratio.

 

[Rob Flinn]

Measuring DCR is not entirely a waste of time.

• Knowing the DCR gives a rough estimate of the nominal impedance. Decent manufacturers make sure the DCR is about 1/10th of nominal impedance.
• Seeing equal DCR at the pri and sec is a good indicator of 1:1 ratio.

Interesting stuff, I stand corrected.  The 1:1 with equal resistances makes obvious sense.    I'm guessing is not entirely foolproof with regards to the impedance.  I was trying to correlate the 1/10th with some specs on the Sowter website & I'm not quite sure how to read it because they spec "TOTAL DC RESISTANCE referred to secondary" in a lot of cases.  Does this mean that they are assuming a certain load i.e 600R ?    Wouldn't the d.c.r  be measured with the transformer out of circuit with no &  would therefore make no difference to the reading?

 

[abbey road d enfer]

Interesting stuff, I stand corrected.  The 1:1 with equal resistances makes obvious sense.    I'm guessing is not entirely foolproof with regards to the impedance.  I was trying to correlate the 1/10th with some specs on the Sowter website & I'm not quite sure how to read it because they spec "TOTAL DC RESISTANCE referred to secondary" in a lot of cases.  Does this mean that they are assuming a certain load i.e 600R ?    Wouldn't the d.c.r  be measured with the transformer out of circuit with no &  would therefore make no difference to the reading?

My understanding is that it's the sum of the actual secondary DCr+ the reflected primary DCr, or to sum it up
Rstot=Rs+(N2/N1)².Rp
In other words, it's the real part of the impedance when the primary is shorted.

 

[rackmonkey]

Testing DCR is always step 1 for me when evaluating unknown transformers. Not only does it give you an idea about nominal impedance of the primary and secondary, as Abbey said, but it also allows you to characterize the winding structure. You can quickly figure out if you’re dealing with split windings, center taps, etc. All of which helps unravel the mystery.

Of course, it’s also how you check for open windings.

 

[living sounds]

I totally respect your wish, but just to let you and everyone know that the stock transformers are quite good.

I agree that the transformers really are not a weak point with these units.

 

[vintagelove]

+1 on keeping the original iron.

I think on GS, someone changed the output transformer on their pultec. It resulted in a high and roll off of 2db. They were apparently happy about this...


I’ll stick with the original thanks.

 

[[email protected]]

Has anyone tried replacing the switching power supply with a linear power supply on the KT ??

 

[abbey road d enfer]

Has anyone tried replacing the switching power supply with a linear power supply on the KT ??

What do you expect from such a modification? Unless you want to tinker for the sake of tinkering, you should have a substantiated motivation for doing it.

 

[[email protected]]

I want to replace all the weak points of the machine