#187

[@WECB640]

26:25 "The boxes are a catastrophe!" LOL!!!!! Stefan, this repair was a great teaching moment. The lack of protection speaks for itself. I don't think I've ever seen an amp that runs class A at low drive levels but changes to class B at higher levels. That was most unique. Yes, a POS. 73 OM

[@dl7majstefan753]

Tnx dr OM

[@hazzy9079]

Thank you for the wonderful advice. I almost switched the speakers to my primary pair after running the hot amp for 5 days, few hours each day. Didnt realise on the lack of internal protection system eventhough i opened the cover to visually inspect the parts. What a great series, enjoyed every second of it. Thank you for taking the initiative and putting in much effort to share it with everyone. You probably saved my speakers that I intended to run the amp with.

[@electronicsoldandnew]

That amplifier is one of the weird ones 😊 designed by golden-eared hifi experts and that regularly have to be repaired by normal people like us. I’ve come across a couple of these and only last week refused to take on another one for a friend of a friend of mine. I just had so much trouble with the two I did that I’ve learnt my lesson 😊 Thanks for the video, and especially the Bode plotting that you did. Really nice function of the scope.

[@dl7majstefan753]

Mni Thanks dr Manuel - yes indeed: weird!! But the sound is said to be "warm" ... hihi. I also wouldn´t take a second one for repair - my need for additional trouble without fun is fully satisfied.

[@rjy8960]

I was surprised by the volume control stage design. Thanks Stefan, this series has been a bit of an eye-opener.

[@dl7majstefan753]

Yes - many things are surprising there!

[@ralphmans]

Stefan, tolles Video, diese Reparatur ist einer der Gründe, warum ich Vakuumröhrengeräte bevorzuge.

[@dl7majstefan753]

Danke! Aber es gibt auch viele gute volltransistorisierte Verstärker.

[@diego.alienigena]

good repair Stefan 👏👏

[@dl7majstefan753]

thanks

[@PapasDino]

The OM must have some strong emotional attachment to this box to have you do all this work and it still be a disaster at best (but a good coffee warmer!). Maybe cheaper/better in the long run to simply buy a better a better amp. TNX Stefan for taking us along for the ride! 73 - Dino KLØS

[@dl7majstefan753]

Hi dr Dino! Yes but the owner (i know him since nearly 50Years - we graduated at the same time at high school) loves it and i don´t know why.

[@PapasDino]

@@dl7majstefan753 Well, there's the emotional attachment...I have some of those kinds of things myself so I guess I can understand or at least appreciate. Happy Holidays Stefan!

[@dl7majstefan753]

Tnx and also all the best wishes.@@PapasDino

[@davidv1289]

Oh. My. God. That is the most ridiculous volume control circuit I have ever seen. You promised more interesting design elements and you did not disappoint. In your list of design flaws you didn't even mention the lack of bias and offset adjustments. I do not think I would trust this amplifier even as a coffee warmer. As always, an interest video - thank you! Regards, David

[@dl7majstefan753]

Hi dr David, Yes! i forgot bias and offset and the bad location of the electrolytic inside(!!!) the heatsink and...and... don´t know what else.. hihi.