Slewmaster - CFA vs. VFA "Rumble"

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Liliya

Member
Joined 2003
jwilelm
Thank you for answering me. Yes, I also think that he used the same schema, but the lay out is quite different. The reason I ask for the lay out: it is much easier when I want to do measurement. When the PCB are populated, it is sometimes difficult where to find R5, D1 etc.

Eivind S.
 
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Shhh its me

Member
Joined 2017
Vrystaat said:
Almost finished. Still need to finalize the face plate with oldskool Sifam DB meters. The amp sounds very good. Mid range and high frequencies are superb. I will connect it on decent speakers and see what happens.:)
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Looks nice and neat, the way I work.

However, [not wanting to be hyper-critical] I see something I wouldn't do in 2nd image.
You have small wires terminating at RH capacitor bank. You have used yellow sleeve pre-insulated crimp lugs. Potential problem here.

  1. This size lug is designed to terminate wire with a cross sectional area of 4 - 6mm2.
  2. The wire there is small, aprox 0.5mm2 [?]
  3. You have used a crimper of 'low order' to effect the crimp. Looks like you have crimped down a couple of times, having a degree of doubt.
  4. You have these wire lugs connected via capacitor terminal to busbar screws. Independent connection of each device or wire is safer practice.
For small wire like this, a red pre-insulated lug is the correct size to use.... even so over sized so the wire needs extra strip, twist and fold to increase conductor size in barrel of lug.
Secondly, wire size should be based on fault current potential, not just operational current loading.
Think of what would happen to the wire if it suffered short circuit to ground or rail to rail short along it's length or at a board trace short in an unprotected [not fuse protected] condition. The wire will act like a long fusible link having the voltage / current of the capacitor bank and transformer supply flowing until it melts. :eek:

Also, hard to see if you have any form of anti-vibration washer under the screws that connect capacitors to busbars.
Perhaps they are there, should be due to the affects of a loose connection, but anti-vibration device such as an internal tooth 'star washer' or spring washer is essential where a mains supply safety Earth connection is made to frame.

Perhaps replicate the yellow lug to that cable size to check how secure the wire crimps in. I've seen similar terminations made where the wire has pulled out under minimal tension loading. [Lug mounted and wire pulled tight]. What increases risk is use of 'basic' or unsuitable type crimpers.
 
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Lecalou60

Member
Joined 2017
Hello Vrystaat,
I just saw your superb amplifier. Really too top. I am a fan of HIFI and I would like to make my audio amplifier of super quality.
I am an electronics technician in my spare time. Could you send me the files of your amplifier so that I can realize it.
I have not read the 10000 post on the Slewmaster and its drivers but I think it is a great choice

Thanks in advance and congratulations again.

Lecalou60
 
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Lecalou60

Member
Joined 2017
Making a Super Audio Amplifier

Hello,
I am a hifi enthusiast and I would like to make myself a super amplifier. I've been watching different forums for several weeks. But the one that most interested me and the Slewmaster with his pre-amp and his diet.
Breathtaking results.
So my choice is based on this type of amplifier.
I do electronics in my lost hours (microprocessor controlled stair lights).
Otherwise my job is to create safety equipment in aircraft.
I hope I answered your questions.

Very cordially

Lecalou60
 
Vrystaat

Vrystaat

Member
Joined 2011
Hallo Lecalou60,
The main output board I have purchased from a group buy on DIY Audio as it is double sided. Someone posted a single sided board that you can build from PDF files. There are also latfet output stages that were posted, I'm not sure if it were Borys that posted them. You will have to search for them, sorry for that.:) Here are about all the different input stages. I have chosen the Kypton ND. Some people say that the Spooky is better. There is also a Slewmaster build thread that you can use.
Slewmaster - CFA vs. VFA "Rumble"
The amp sound really good and has plenty of power !
Best of luck :)
 
keantoken

keantoken

Member
Joined 2006
OS had a brush with his mortality which sent him off into the sunset on a bicycle. I say good for him, everyone needs a break.

I definitely wouldn't feel entitled considering everything he has given away freely for years. Not to implicate anyone but just thinking aloud. Some people work and work until they are so sick their body forces them to take a long break.
 
Tournesol

Tournesol

Banned
Joined 2017
I followed this thread silently since very a long time. So I know a little the story.
I just worry about him and his health. No new message on his Facebook since 7 months and the last one was worrisome. So, if someone is in contact, i would like to have news and let it be passed on to him that he is not forgotten.

Best regards,
Tournesol.
 
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thimios

Member
Joined 2009
Tournesol said:
I followed this thread silently since very a long time. So I know a little the story.
I just worry about him and his health. No new message on his Facebook since 7 months and the last one was worrisome. So, if someone is in contact, i would like to have news and let it be passed on to him that he is not forgotten.

Best regards,
Tournesol.
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I worry about him also:(
I hope he is healthy.
 
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