Rohde und Schwarz Begrenzungsverstärker ABR / U23

[TwentyTrees]

Great stuff Falk, and congratulations on the exciting news about your family!

I think I'm in the same boat as @JMan - while a "tips and tricks" note would be very helpful, a full assembly manual would probably not be necessary. I would certainly be in for a group buy on the power transformer.

Now to try and find 6U of rack space...

 

[labak]

Congrats for best project of your life...This is the most important...
No assembly guide and up for whatever help you need to make that run coming out (Group buy etc...)

 

[protools]

Hello Falk, some news, thanks to let me know.

 

[SKJGProject]

can't wait to build this thing finally....

 

[JMan]

I know life gets in the way of best-laid plans, so no pressure, but I'm still just waiting with just as much excitement as the folks above in hopes of building a pair myself. Is there any news on the project?

 

[Falk]

Good morning,

after becoming dad and studio owner this year, which both was totally underestimated regarding time consumption I finally found time to make a plan.

End of December I will meet a GDIY member to measure voltages in his original U23. This will give me a final confirmation, that the path I went with the both prototypes is the right one. Early 2024 I will build another unit with the revisioned pcbs and update the mouser BOM. I will also build this unit with UTM transformers and compare with the Edcors.

Once this process has ended, I will print PCBs and send them out.

I ll keep you posted as soon as one of the the upcoming steps has been made. Thanks for your patience but the project will come next year.

Best,
Falk

 

[opacheco]

Good morning,

after becoming dad and studio owner this year, which both was totally underestimated regarding time consumption I finally found time to make a plan.

End of December I will meet a GDIY member to measure voltages in his original U23. This will give me a final cofirmation, that the path I went with the both prototypes is the right one. Early 2024 I will build another unit with the revisioned pcbs and update the mouser BOM. I will also build this unit with UTM transformers and compare with the Edcors.

Once this process has ended, I will print PCBs and send them out.

I ll keep you posted as soon as one of the the upcoming steps has been made. Thanks for your patience but the project will come next year.

Best,
Falk

Falk Excellent news!!….Please inform us of any progress.

Thanks
opacheco

 

[gyraf]

..and let us know if you need support..

/Jakob E.

 

[Falk]

I thought a bit more of how to deliver the boards.

Var 1: The boards come without PSU - this would be very simple for me but everyone would need to invent a PSU and order their own power transformer.
I could also pre finance the whole project and you would need to pay just before the shipment. (I estimate 60€ excl. VAT per channel)

Var 2: The boards come with PSU and toroidal. This would be better for trouble shooting and the PSUs work stabile since two years. Also in summer.
This would mean that I would need at least a non refundable down payment to be able to pre finance 30 toroidals. (I have 15 people on the list for 2 units each - who hasnt wrote me a mail until now, please declare your unbinding interest and mail to [email protected]) (I estimate 175€ excl. VAT per channel)

Var 3: I provide boards, psu, toroidal, chokes (2) and transformers (4) - this would mean you would need to pay the whole package beforehand. After gathering the money I would order everything. After waiting for all the parts to arrive I would ship all the orders. (I esitmate 450€ excl. VAT per channel)

I will only offer one of the 3 options after we decided for one. So please let me know wich option you prefer. The price estimation are not very much based on real world prices so please dont be resentful if they change for the worse in the end. Its also possible that it will become less.

Best,
Falk

 

[JMan]

Hey Falk,

For me, option two looks best. It would be nice if all of us were building using the same PSU circuit, since it would eliminate a great deal of potential confusion amongst builders trying to troubleshoot.

Option three is nice, but would be harder to finance up front (for me, at least). Also, I'm in the US, and if I remember correctly, you used Edcor transformers. I think you're elsewhere in the world, right? So perhaps for someone like me, it doesn't make sense to have the transformers shipped to you just to be sent right back to me in their country of origin, increasing the cost (not to mention carbon footprint) unnecessarily.

My 2 cents.

I know I've expressed my interest on the thread a few times, but I'll also send you an email. Thanks for all of the time and energy you've put into this, all the more so now that you're a dad!

J

 

[thomasdf]

Awesome news all around, bravo !
Option 1 or 2 seems the best, for sure.

 

[Falk]

I would prefer Var 2 too. Also its nice to keep the variance of used iron high.

 

[TwentyTrees]

Thanks for the update! Option 2 looks good to me. Cheers!

 

[Gold]

Option 1 or 2 is fine with me.

 

[echoplex]

Hey Falk,

Option 2 is also fine for me. Congratulations for the fatherhood too
Happy to see this project still being active.

 

[michinger]

Option 2 or 3 would fine for me.

 

[echoplex]

@Falk do you think it's possible to build a dual mono version and fit two boards into one case?
power supply in the middle like in this Electronaut M63 for example?

 

[gyraf]

I'd expect dual-monoing would open a whole new can of worms

 

[echoplex]

I'd expect dual-monoing would open a whole new can of worms

I hear you.. you probably mean in terms of interferences and such, right?

 

[gyraf]

Yep, and grounding scheme complexity..