SlewMaster Builds

[TonyTecson]

Fuses in the secondary side have to survive the initial charging of the capacitors fitted after the fuses.

Let's say you have 15mF for the smoothing but this is before the secondary fuses, then that 15mF does not blow the fuses
Let's say you have a total supply rail decoupling of 1320uF. This has to be charged through the fuses.

another way of looking at this, fuses can protect the power traffo in the event
of catastrophic failure of the rectifiers...

 

[AndrewT]

another way of looking at this, fuses can protect the power traffo in the event
of catastrophic failure of the rectifiers...

A mains fuse will limit the energy input to the primary very effectively.

Use a properly rated mains fuse.

 

[AndrewT]

Any news from Pete?

he is on the other side of that mountain !
and enjoying the view without us interrupting.

 

[thimios]

he is on the other side of that mountain !
and enjoying the view without us interrupting.

I hope he is healthy doing whatever he love.

 

[Vrystaat]

Kypton nd vs Spooky

I have build both and have tested them, but not before blowing the test speaker. I forgot to connect the feedback to the Spooky IP board and there were just one monstrous shriek and then quietness. So out with a better speaker then.
I have found the Spooky very good and with a tad more bass overall than the Kypton. But my choice is still the Kypton. Good bass and very good mid and high frequencies and bit more clearer than the Spooky. At least now I can put my mind to rest and enjoy the music ,otherwise I would alway's have wondered which is the best for me. The proof is in the pudding !!

 

[kimschips]

I have build both and have tested them, but not before blowing the test speaker. I forgot to connect the feedback to the Spooky IP board and there were just one monstrous shriek and then quietness. So out with a better speaker then.
I have found the Spooky very good and with a tad more bass overall than the Kypton. But my choice is still the Kypton. Good bass and very good mid and high frequencies and bit more clearer than the Spooky. At least now I can put my mind to rest and enjoy the music ,otherwise I would alway's have wondered which is the best for me. The proof is in the pudding !!

Great to hear with your project i am also using Kypton C with slewmaster😎
The silky and clean sound is very very nice.

Please use a dummy load and a sinewave generator, osciloscope next time so you loose fine gear☺

 

[Vrystaat]

Hallo Kim, I have all the tools but one gets complacent and in one stupid move you forget something like the feedback.

 

[Harry3]

Thanks for the comparison Jan.
Run the Spooky for a week and see if the sound changes.

Cannot wait to finish my amp.

 

[kimschips]

Hallo Kim, I have all the tools but one gets complacent and in one stupid move you forget something like the feedback.

Yes i Know that too Hehe
Best regards😊

 

[Samuel Jayaraj]

Just a question which might have been covered earlier in this long thread:

Can the Output Stage of the Slew Master Amp, either BJT or Mosfet, be run Open Loop for reliable and safe operation? Thanks.

 

[vzaichenko]

Just a question which might have been covered earlier in this long thread:

Can the Output Stage of the Slew Master Amp, either BJT or Mosfet, be run Open Loop for reliable and safe operation? Thanks.

Hi Sam,

Yes - Slewmaster OPS is a follower, that can be run outside the global feedback loop. Note that in this case, both distortion level and output impedance reduction effects, provided earlier by the global feedback, will not be in place.

Cheers,
Valery

 

[Samuel Jayaraj]

Thank you Valery. Understand about the damping factor coming down. But it will be nice to listen with and without feedback. Feedback of VAS and output being run open loop, actually sounds very good.

 

[Liliya]

Today I did some work on one of my two Slewmasters. This one is with the Spooky IPS.
Unfortenatly the PD+ connection(screw) to the OPS(Arc Welder five pair output) was disconnected, and when I fired up the signal was very much distorted. After a while this channel is now silent. I am sure that it is something wrong with the Slewmaster, because the loadspeaker protection lights up when I disconnect loadspeaker out from the Slewmaster. I will start to search for failure, but first ask members what would be a good starting point. What transistors would be the best to start up examine/measure on?

Eivind S

 

[Liliya]

The thread is very "dead" for the time being.

Eivind S

 

[jethari]

Elvind,
Start with the output transistors, at least one of them must have blown.

Hari

 

[savvas]

You could check the IPS first. Jeff gave some notes in this post

 

[jan.didden]

Why don't you start by measuring the DC out on the speaker output? That's a standard test to rapidly find out if there is a short to + or -, or somewhere in between. That will immediately tell you in which direction to search further. It is called 'fault finding'

Jan

 

[jkuetemann]

You can also test the input and output boards in isolation which will assist in narrowing where to look.

 

[Liliya]

Thanks to good advises so far. Measuring DC output was on my list. Separating IPS and OPS and repeat the tests/measurements from the first time I run the Slewmaster is also on the list. I will start there and may be come back to new questions later on.

Eivind S

 

[tonza75]

SpookyIPS servo is bs. Osripper played with ltspice, thimos and still4given had AB setup and said they all sound the same proved with oscope that these work. Or arta. Osripper said what to Change with ltspice and many did so and said it works.
There are YouTube vids of amps try to find 5pair OPS with so cal led proven to work on YouTube.