Kuartlotron Error Correcting Super Buffer

[saheb11123]

Any updates on the pcb's ?

 

[Project16]

Hello everyone!

omishra:
Very well your circuit layout! :clapping:

If some are interested here is my latest PCB Kuartlotron and I guarantee that with my Borbely-Sulzer supply, everything works perfectly, the sound is superb and no hiss or noise.

Regard's!

 

[sachu888]

Any updates on the pcb's ?

I will post update here as soon i receive them. It will take time.

Regards
Sachin

 

[saheb11123]

Cant wait too excited

 

[quad]

Hello everyone!

omishra:
Very well your circuit layout! :clapping:

If some are interested here is my latest PCB Kuartlotron and I guarantee that with my Borbely-Sulzer supply, everything works perfectly, the sound is superb and no hiss or noise.

Regard's!

Project16, welcome to the forum and thanks for sharing your layout

 

[Project16]

Yes, almost all of failed preamps and phono preamps are due to bad power supply or noisy transformer. I tried orientation of transformer also matters where no parts or PCB coming in direction of axis of transformer coil. i.e. direction perpendicular to top surface of EI transformer. Likewise joint were E and I meet, these leak more magnetic flux to disturb other sensitive circuit. To get 100% silence, layout also plays role.

The power actually has a very important role but a simple molded transformer located near the same components poses no problems.
The picture shows my Borbely-Sulzer and I can guarantee that on my phono RIAA or Kuartlotron no breath, buzzing, etc ... can be heard (the silence is total).
If this power supply are interested I can provide offset films.
For information I designed a version with the transformer on the card and another with no trransformer. This very stable power supply is adjustable and is provided with a soft start.

Regard's!

 

[jls001]

Thanks, Project16. Nice to see you here:thumbsup:

I changed the EI transformer to an R Core. The nature of the noise has now changed - earlier with EI most of the noise came from the woofer with almost no noise from the tweeter. With the R Core the overall noise has come down, but a good percentage of the noise is now generated by the tweeter, and the woofer sounds subdued than before. I use the same type of R-Core with same rating, but from a different manufacturer, for my DCB1. PS circuitry is same on both (omishra's OPS - LM317/337 based). As already mentioned before on the thread, my DCB1 also has some noise and now I realise that it is very similar to the noise I hear on the Kuart after I changed to R Core.

I think what is needed is a sealed transformer. Need to figure out a source.

And to repeat what I had said earlier - this noise is low. Cannot be heard unless one goes very close to the speaker drivers. So it does not in any audible way interfere with the music. But all the same I'm keen to eliminate it completely or at least to a point where it doesn't bother my brain anymore

 

[manniraj]

Thanks, Project16. Nice to see you here:thumbsup:

I changed the EI transformer to an R Core. The nature of the noise has now changed - earlier with EI most of the noise came from the woofer with almost no noise from the tweeter. With the R Core the overall noise has come down, but a good percentage of the noise is now generated by the tweeter, and the woofer sounds subdued than before. I use the same type of R-Core with same rating, but from a different manufacturer, for my DCB1. PS circuitry is same on both (omishra's OPS - LM317/337 based). As already mentioned before on the thread, my DCB1 also has some noise and now I realise that it is very similar to the noise I hear on the Kuart after I changed to R Core.

I think what is needed is a sealed transformer. Need to figure out a source.

And to repeat what I had said earlier - this noise is low. Cannot be heard unless one goes very close to the speaker drivers. So it does not in any audible way interfere with the music. But all the same I'm keen to eliminate it completely or at least to a point where it doesn't bother my brain anymore

Joshua, even I am hearing from the time I got the DCB1 and a top mounted tweeter in my Frugal Horns. I was thinking that its the tweeters fault but now I can relate it to the R-Core as you rightly pointed out. The noise is not much but when the song is paused or not playing I can hear it coming out from the tweeters. Before the tweeters were installed I never got this noise or did not give much of a thought.

 

[keith_correa]

I changed the EI transformer to an R Core.

Does the R-Core that you used have separate bobbins for primary and secondary? Some of the so called R-Core's that are made to order are not implementing this.

 

[captrajesh]

The nature of the noise has now changed - earlier with EI most of the noise came from the woofer with almost no noise from the tweeter. With the R Core the overall noise has come down, but a good percentage of the noise is now generated by the tweeter.

Could the noise be because of the PTP wiring where it is somehow getting inducted into the circuit?

I think what is needed is a sealed transformer. Need to figure out a source.

I think R Core has a good amount of shielding owing to the design. I'm with what Keith said below.

Does the R-Core that you used have separate bobbins for primary and secondary? Some of the so called R-Core's that are made to order are not implementing this.

Even I read about that before.

 

[Anil kumar]

I am using R core in my LM 3886 chip amp build, i have no issues. I'ts absolutely silent.

 

[Project16]

PS circuitry is same on both (omishra's OPS - LM317/337 based).

I think that a supply with only regulators (LM317 / LM337) is good but not enough for this kind of installation (preamplifier) because these regulators can not totally eliminate ripple.
A precontrol as shown below already gives much better results.

I also made a PCB for this pattern!

PS: I will prepare all the files from my power (diagram, layout, etc ...) and I'll open a thread to propose because some will be interested I think.

 

[quad]

I think what is needed is a sealed transformer. Need to figure out a source.

Here's a nice phono pre chassis posted on diyaudio -

Post your Solid State pics here. - Page 421 - diyAudio

 

[jls001]

Does the R-Core that you used have separate bobbins for primary and secondary? Some of the so called R-Core's that are made to order are not implementing this.

Yes, it has.

 

[TD150]

Guys last update seems a month ago.
Any further progress on the project?

 

[sachu888]

I have received the PCBs few days back. I also ordered parts couple of days back. Sorry I could not do it earlier,due to urgency at work and home. It could take another 10 days.

Regards
Sachin

 

[saheb11123]

Please give us the final price of the kit (teethy grin)..

 

[sachu888]

Sorry for updating the thread very late. Here are the PCbs I received few days back.





I am still waiting for parts. I hope I will receive them in a week's time.

Regards
Sachin

 

[saheb11123]

Good news. Pcb's looks good.

 

[sachu888]

Update

I am waiting for couries. Element14 has shipped it on 7th, and I still have not received it. I have raised a complain regarding this. Its been more than a month since I order parts.
I will start sending kits as soon as I receive the courier.

Regards
Sachin