Hiraga 30Watt build… can't get it right (help!)

[Citizen124032]

Well done, learned an extra bit, sourcing for CRC resistors for improvement. Enjoy!

 

[Smaragdkade]

Indeed!

last mod before i can go listening again. Mounted the drivers on the chassis. Thermally this part of the chassis is not soo much thermally coupled to the heatsink, so i dont expect thermal runaway. The drivers stay cool now, temp measured 35C after 1 hour running (was 60C). I had to lower the 33K resistors on the base of the drivers to 28K to get 1.1 Amp current. No drift on the output whatsoever! Humm gone, ringing gone, drift gone

(dont mention my terrible solder job on the drivers ;-) That will be fixed in de next version)

 

[Citizen124032]

That's fine!
Make sure that the styroflex 68pF caps yellow side is on the lowest impedance node (its the outside foil).

 

[Smaragdkade]

Tonight first listening after all mods! . Found out during testing on my workbench that with closed top cover temps go up to 50C inside, thats too much for me, so I put a new topcover on. 40C now, wich is much better. This thing weighs a hefty 25 kilograms :-( so I hope I dont break my back.

 

[jacques antoine]

I put a new topcover on

Did you drill all the million holes in the top cover yourself?

 

[Smaragdkade]

Hahahahaha nooooo. One of the sortof design goals was to make the chassis from stuff from my local hardware store. my LHS had aluminum panels with predrilled holes so ... its 1mm thickness thou , but who cares.

 

[jacques antoine]

So how does it sound ?

 

[Citizen124032]

So how does it sound ?

The top cover with all the million holes?
(I only count 2294 holes)

 

[Smaragdkade]

So how does it sound ?

Im amazed!. By no means I'm no expert, but the last 35 years i listened to some speakers, amplifiers and whatever audiophile components (in the 1000/2000 Euro range), this amp sounds very very good. Very daynamic, lots of decay, huge soundstage placing and detailing..... and Ive only listened to one CD a really know well :

https://www.muziekweb.nl/en/Link/JFX0871/Because-of-you?TrackID=JFX0871-0006

Very nice chesky recording. Sounds the best so far on this amp (as far as I can remeber.)

 

[Smaragdkade]

Bamboo front panel sponsored by IKEA and cut to size by my LHS. Top cover strips adding. Bought some spray paint black to make top cover and cooling fins look better.

 

[Smaragdkade]

project ended for now. Sounds fabulus on my KEF reference 101's and my audiostatics 100. Added new frontplate and velleman DC protection for the speaker outputs and that works just fine. Now, new project, philips CD player TDA5141A with some mods. tnx for your help making this work ! ;-)

 

[jacques antoine]

Mondrian style amp: neat!

 

[amplidude]

Fine looking amp, and top cover is perfect for drying nuts..👍
I have the 30w super also, but its without chassis, been so few 2 years, I think the hardest diy part is getting the chassis just right, and damn finished chassis are expensive.

 

[Smaragdkade]

tnx, I had the same challenge...so i just went to my lhs .....they had all kinds of stuff to build a chassis, like alu profiles, connecting stuff.... squires etc

 

[huggygood]

Mondrian style amp: neat!

+1

 

[amplidude]

Would be a shame to cover up the output transistors , 2sc2608/2sa1117.
Collector soldered to case, works like a charm

 

[jacques antoine]

Is it proper to solder metal subjected to thermal cycling?
I would have used one of these on the screws:

 

[amplidude]

I took a chance, I made the super leach before this and got rather annoyed by that way of connecting 16 T03's