Building a symmetrical PSU B1 buffer

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#1,861
Hi regiregi22, me too 😉
Before, I've to power up my LightSpeed too, I'm in lack of 5V PSU.
Could someone point me a scheme for wiring DCB1 and LightSpeed PCB ?
Thanks !!!
 

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#1,862
Pics of the build in progress...
As you can see very "high" built. I've planned to cut Mosfet's legs, same operation for 2SK170BL.
Another point concerns the free space between the LT7812 and the right Mosfets sink : find a heatsink that fits !
I'm using 5V relays and the LT gets hot.
Heatsinks are recycled, they came from old Compaq Proliant PSU, hand saw cutted yesterday.
Do you think it's a good idea to thermally coupling the 2SK170-BL quad ?
 

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#1,863
more recommendations for new big blue mez layout

@salas, @ teabag?

can the layout silkscreen be modified to show the polarity marks for polarized caps (e.g. the 4700uf main filters) outside of the component outline circle? otherwise, polarity indication is covered when components are installed.

also is there a provision to add (hopefully 2nd order) lpf (~50kHz) rc filter @ FET gate. i have a problem with my current amp and/or pre (both have >100 kHz BW) where the my highly imperfect source (CD/DVD combo unit) is raising the noise floor and was hoping the new BigBlue could fix that while improving the system resolution.

thx,
Tincanear
 
#1,865
korben69 said:
Pics of the build in progress...
As you can see very "high" built. I've planned to cut Mosfet's legs, same operation for 2SK170BL.
Another point concerns the free space between the LT7812 and the right Mosfets sink : find a heatsink that fits !
I'm using 5V relays and the LT gets hot.
Heatsinks are recycled, they came from old Compaq Proliant PSU, hand saw cutted yesterday.
Do you think it's a good idea to thermally coupling the 2SK170-BL quad ?
Click to expand...

Bend the LT forward a bit and bolt one sink on it.🙂 Nothing to really gain by coupling the quad IMHO, its not about a differential amplifier.
 
#1,866
tincanear said:
@salas, @ teabag?

can the layout silkscreen be modified to show the polarity marks for polarized caps (e.g. the 4700uf main filters) outside of the component outline circle? otherwise, polarity indication is covered when components are installed.

also is there a provision to add (hopefully 2nd order) lpf (~50kHz) rc filter @ FET gate. i have a problem with my current amp and/or pre (both have >100 kHz BW) where the my highly imperfect source (CD/DVD combo unit) is raising the noise floor and was hoping the new BigBlue could fix that while improving the system resolution.

thx,
Tincanear
Click to expand...

But the installed caps still have marks on their jackets I guess. Yes if we ever run any new GB and CRT is accessible we can fix that.

If we cut the bandwidth it sounds lazy. That is why we don't do it with more than 20-25K pot. Why not putting an input filter in the specific amp than to cut all DCB1s?

P.S.

What Blue Mez? Now people want a Blue Mez? Here we go again...🙂
 
#1,867
Salas said:
But the installed caps still have marks on their jackets I guess. Yes if we ever run any new GB and CRT is accessible we can fix that.

If we cut the bandwidth it sounds lazy. That is why we don't do it with more than 20-25K pot. Why not putting an input filter in the specific amp than to cut all DCB1s?

P.S.

What Blue Mez? Now people want a Blue Mez? Here we go again...🙂
Click to expand...

Sorry, Salas, but i've been away from this thread and am a bit confused about the next planned BigBlue pcb. is this hypno (w/o input selection) or mez (relay driven input select)? i don't want to start another debate-- i just want to be able to get the latest & greatest pcb and finally start building up something...

thanks,
tincanear
 
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#1,869
korben69 said:
Pics of the build in progress...
As you can see very "high" built. I've planned to cut Mosfet's legs, same operation for 2SK170BL.
Another point concerns the free space between the LT7812 and the right Mosfets sink : find a heatsink that fits !
I'm using 5V relays and the LT gets hot.
Heatsinks are recycled, they came from old Compaq Proliant PSU, hand saw cutted yesterday.
Do you think it's a good idea to thermally coupling the 2SK170-BL quad ?
Click to expand...
I really love those heatsinks, it reassembles some kind of V8 engined car.

Oh, and I don't need a heatsink for the LT7812. Is runs at ambient temp even after some hours turned on. I'm using a 12v relay though.
 
#1,870
Posted this on the GB section, this thread is probably more appropriate..

Ok, been stuffing the boards with parts I have available. If we are looking at the board horizontally on top right IRFP240 it looks as if there is an insertion hole missing for one end of the 470r resistor.

Also, the BOM states that there are 4 sk170 matched, where on the board do they go?

BOM does not have a part number for the relay, does anyone happen to have for mouser or digikey, please?
 
#1,873
Yes. Near relay. The whole Buffer part (the rest power supply) is after the VOut* seen on right of pic. So all to the left is the buffer, not much to it. The Vout* jumper (white stripe) must be applied in order for Buffer to power up. Otherwise it's just a nice shunt reg supply. There are two other jumpers that need to be done in the power supply as well.
 
#1,874
Salas said:
I think Alon has a board like that? Maybe he can let you know if he reads.
Click to expand...

Hi Just saw this!!! Sorry Korben69

Its very difficult to explain, but if you havnt already set up your dcb1 with optivol, you could try having a look at page 167 post 1665 There i have posted some pics of my build...the pics are not very good quality, but you can see how the two are connected together. If you cant quite work it out by looking at the pics, then pm me and i will try to explain 🙂

On a side note, I would highly recommend powering the optivol, with a Salas Shunt reg set to 5v...i tried quite a few combinations of power supplies for running the optivol and by far the best was removing the power supply section of the optivol board and running direct with 5v salas shunt reg, i did try the salas shunt reg set to 8v as a prereg, and then this went into the optivol 5v supply, but this did not sound as good. Pics to follow.

Alon
 
#1,879
Thank guys you for your answers 😉

Malka07, I'll send you a PM for my built, your help will be great. Very nice result, I like the "Zen look" !
I use a Mezmerize board not Hypnotize. I'll try a GoldMinireg as PSU for the 5V.
Your pics show that you've wired the LDR Output(L/R) to the Hypno Input(L/R).
How should I proceed with the Pot on the Mezmerize PCB ?
Should I just ignore it ? 😕 😕

sandbasser, the LT7812 gets a little bit hot when using 5v relays : heatsink recommended.
My mistake, the tansformer is 2x15v. 2x12 is a typo. Some Selectronic RCore are oversized as mine, 2x15v gives about 19.5v at the output...

Salas, yes, bending the LT is the right solution. I'll give it a try.
 
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#1,880
sandbasser said:
A couple of questions:

The "Blue" Hypnotize BOM specifies a 2x15 transformer while the 'original' Hypnotize-Mezmerize specifies a 2x12. What's different???

Can someone please summarize the pros and cons of the 12v relay vs the 5v relay??

Thanks,
Click to expand...

The Blue is geared up towards heavy use so it will be certainly sinked, thus more Vin to Vout created by a higher Tx makes it regulate in more ample margin without caring for some extra dissipation. They will run it up to 1amp some, wait and see...

12V will create less dissipation on its feed components. 5V option is when you can't find 12V cheap or available at a time. Basically there was a sub GB for 5V ones back then so we catered for both. 12V is the natural choice.
 
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