What’s On the Bench Tonight (OBT)

[nigelwright7557]

Got my Maplin 75WRMS update amplifier on my bench.
I took the original Maplin circuit and added front end RC decoupling to get rid of residual hum. Add DC bias pot. Added option for TO247 or TO3 transistors.
One of the best amps I have heard.

 

[puijkh]

Hi Puijkh,
If your planning to use the Yarra/M2X mounting pattern, the V- is not in the correct position.

Hi Vunce,

Thanks for looking, you are absolutely right, my brain was somewhere else when i moved the in connection. The V- must also move to the left.

So going for a 4th revision.

 

[Gyuri]

For me, MAKOP virus was on the bench in the last days and nights.
I killed it, and all of the data recovered from backup.
I hope so.
Hope is the most beautiful word.

 

[puijkh]

M2x / Yarra Experimenter board V4

Thanks to Xrk971, JPS64 and Vuze getting into the right direction.

 

[xrk971]

Got my Maplin 75WRMS update amplifier on my bench.
I took the original Maplin circuit and added front end RC decoupling to get rid of residual hum. Add DC bias pot. Added option for TO247 or TO3 transistors.
One of the best amps I have heard.

I have never heard one of these Maplin’s. Do you have a link to a schematic?

 

[xrk971]

For me, MAKOP virus was on the bench in the last days and nights.
I killed it, and all of the data recovered from backup.
I hope so.
Hope is the most beautiful word.

Sorry about that, Gyuri! Glad you were able to recover your data!

What AV software do you use? I have used Avast for past 5 years. I upgraded to the paid version. Seems to be good so far.

 

[xrk971]

M2x / Yarra Experimenter board V4

Thanks to Xrk971, JPS64 and Vuze getting into the right direction.

Thank you for making this! This looks really handy.

 

[xrk971]

WOBT - June 7, 2021: this is actually on Vunce’s bench. The LuFo amp PCBs arrived. These are huge mirror symmetry boards designed to fill the length of a 300mm deep UMS heatsink. JPS64 made another masterpiece in elegance and simplicity. I think these boards might hold the record of 21,000 vias.

 

[xrk971]

I know that this is on Vunce’s bench tonight. The LuFo is going inside a gutted Stratos chassis.

 

[poseidonsvoice]

So awesome! Great use of that Stratos chassis

And Vunce uses the same soldering iron system I do! It's a dream to work with! Great work Vunce, looking forward to your build.

Best,
Anand.

 

[nigelwright7557]

Just built up a JLH1996 class A amplifier.
Didnt work so a careful visual inspection first showed a MPS92 in wrong way around.
So replaced it and it still didnt work.
Checked all components and found a bad trimmer.
Replaced it and amp burst into life.
Trimmer was ebay's best so maybe not unexpected that its faulty unless transistor wrong way around blew it.

 

[xrk971]

Hi Nigel,
I have only made a JLH headphone amp, and for a $20 kit - it sounded fantastic. Good to hear you got the bugs worked out!
Thanks for sharing.

 

[xrk971]

So awesome! Great use of that Stratos chassis

And Vunce uses the same soldering iron system I do! It's a dream to work with! Great work Vunce, looking forward to your build.

Best,
Anand.

It’s always cool to see other people’s work benches!

 

[Vunce]

Hey Anand!

So your familiar with Stratos, Hehe. The chassis is a monster, I knew it would come in handy some day. The positioning of the components is not set in stone, I just wanted to make sure everything would fit in side with the lid on.
I love my Hakko also! Switching tips takes 5 seconds and the selection of specialty tips, especially for SMD components, is fantastic.
Just received the parts to start the verification build, slinging solder this weekend

Cheers,
Vunce

 

[poseidonsvoice]

On the bench...MOFO biasing

Best,
Anand.

 

[suresh]

Anand,
your work bench looks professional. Doctor or Engineer ? Congrats and
Hats off .

 

[poseidonsvoice]

Anand,
your work bench looks professional. Doctor or Engineer ? Congrats and
Hats off .

Thanks! I took the day off today to work on my MOFO , and yes...physician! How perceptive!

Best,
Anand.

 

[xrk971]

Hi Anand,

That’s a lovely bench ! Clean enough to operate on!

What is that choke you have?! Looks like a flat copper foil winding?

I see you have the same LED binocular magnifiers that Vunce and I both use.

I see you use JBL LSR 305’s to listen while soldering. Nice.

Prasi’s Mofo board looks great!

Thanks for sharing.

 

[Vunce]

X, That’s a Lundahl.
I use the same ones

Anand,
I will have to clear out my work bench clutter before anymore picture get out, LOL!! Beautiful work area you have

 

[xrk971]

WOBT - June 11, 2021: The LuFo PCBs are here! I’m going to start populating them. These boards are impressively huge. JPS64 did superb job. We have a few silkscreen errors but that’s the point of verification builds. We work out all the bugs before releasing proven-to-work designs for all to enjoy.

Did I mention that I ordered these monoblock chassis? Will be 3 weeks or so before they get here.