Aleph J Schematic

[Zen Mod]

...

Anyway how safe is to use anodisation as electrical insulator?

do not .

buy Keratherm pads from Zhoufang .

 

[schultzsch]

Thank you Zen Mod for your quick answer.Was just preparing to drill another hole 😀

I have at hand some kapton tape but is sticky at one side and I`ll want to use this with thermal grease between heatsink - tape and tape - mosfet.From what I read Kerafol Keratherm is better than mica(kapton) but I`ll have to do another order and wait at least 2-3 weeks and to be sincere I am fed up waiting and my budget is pretty limited.
So what do you suggest?(you already did but...not in this situation meaning my budget limitation and time)

 

[Zen Mod]

use kapton if you have it

clean that sticky film with some solvent

you can use silicone grease if you want , it will not make any harm 😉

 

[jacco vermeulen]

Anyway

+ if you are concerned about thermal resistance, grind the anodising off where you mount the output devices (and/or polish the blank surface right before you mount the insulator/device).

For changing the bias, the whole idea of this DIY endeavour is to get a grasp of what you're doing.
Early on in this thread it has been mentioned (4-eyes, as usual) that the 68Ksomething can be replaced by a lower value and a trimpot to fiddle.

 

[schultzsch]

Thank you guys for the tips
I think i will try to grind the surface like jacco says even if the layer of anodisation is very thin I think it will count on thermal resistance.
As for R27 I have ordered multiple values between 70-140K Vishay RN55D...Just wainting for them to arrive.

 

[jacco vermeulen]

Do a search for : lousy Aleph to Babelfish

(also from that you know what)

 

[abarth92]

This amp is good only in winter instead of heating (i'm joking) 🙂.
Will also sound good because it's an A class amplifier.
I remember my 2 LM3886 has a much cleaner sound than the tda8560

 

[bobodioulasso]

As for R27 I have ordered multiple values between 70-140K Vishay RN55D...Just wainting for them to arrive.

With R27 stock value (68k), bias is about 1.2A per leg.
The smaller R27 the lower the bias.

 

[jacco vermeulen]

(also depends on the choice for the Alphie current source device, ZTX450 does 0V64 Vbe at 4mA, things like BC550 punch in at 0V7)

 

[bobodioulasso]

Ztx used.

 

[schultzsch]

Do a search for : lousy Aleph to Babelfish

(also from that you know what)

I did a search for the words on google and the returns were : now I am a real First Watt guy...... - diyAudio and Pictures of your diy Pass amplifier - Page 3 - diyAudio

at which of these do you refer? can you please give me a direct link?

Thank you

 

[Zen Mod]

just search for Babelfish in Pass Forum , thread titles only

or look here : Babelfish J

 

[jacco vermeulen]

Pfff, tiresome.
http://www.diyaudio.com/forums/pass-labs/75281-babbelfish-j-pcbs-8.html#post1112763

(good thing i'm heading for South-Amerigo in not so long)

 

[Zen Mod]

.....

(good thing i'm heading for South-Amerigo in not so long)

again ?

 

[jacco vermeulen]

Si.

Me have huge LP & Maxi single collection from this place, bought 1st one when i was like 18.
=> Errol Burger & The Exmo Stars - djaroesoe - YouTube

(friends have business sideshow there, normally go over twice annually, this year they'll stay three months. Good chance they will go live there permanently in near future, is my guess)

 

[schultzsch]

Very interesting tutorial Mr. Aleksandar. It is so nice of you to share with us. Really appreciate it and thank you for your kindness.

I wish you a good trip mr. Jacco

 

[eyoung]

1000 grit emory paper on a piece of glass and mineral oil to polish the scratch out then clean and use insulator of your choice...

regards, E

 

[schultzsch]

finished soldering...

 

[schultzsch]

I have a little problem.At the output i get 27.3 volts dc and across r7 57mV.What could be the problem?
I have checked everything...

 

[schultzsch]

and Q2 gets hot