Salas, if i want to adapt the power supply used in DCB1 for +/- 5V what changes i need to do ? The source used in RIAA preamp seem a bit simpler but is as effective as this one used in DCB1 ?
Sorry if i am a but offtopic but lost between your threads.
Adrian
You should use 2 leds and a diode instead of 5 leds and it will give you 5V if you must, but BIB is better for a general reg.
Erlend,It is possible to increase gain in the NCORE. Just read the manual.
Could you tell me where it talks about that? I don't see it. Also what would be the possible ramifications?
DCB1
Happy to report I have hooked it up to my second system and it is now statring the burn in process. Sounding pretty darn nice.
After burn in I will bring it in and take a listen on my main system. Then more than likely go to 600ma or more and upgrade to TX resistors. And report back.
At that point I will put in enclosure.
Nice project! Thanks Salas and Tea Bag
Happy to report I have hooked it up to my second system and it is now statring the burn in process. Sounding pretty darn nice.
After burn in I will bring it in and take a listen on my main system. Then more than likely go to 600ma or more and upgrade to TX resistors. And report back.
At that point I will put in enclosure.
Nice project! Thanks Salas and Tea Bag
Check the output Mosfets.
On the 9140,140 closest to current limiting resistors I get 3.6v and 4v. The other two, I get 0v (checking 1st and 3rd pins, which should be G,S correct?).
Not sure. What caught me first was a slight smell of burning after about 30 seconds. I actually got a few seconds of music then it cut out and that's when I checked and saw the leds were out. I did discover afterwards some of the fets had become a little loose - the bolts needing more tightening.
Which fets need replacing?
Which fets need replacing?
Those with 0Vgs towards the audio part of the board nearer to 5 Leds each. Use thermal paste and check them well for good insulation pads and good but not overt tightness.
Ok, makes sense as I think those were the two that had gotten a little loose. Thanks Salas.
I will. It may not be enough actually. I am going to back down to 600ma or so until I figure out a proper solution.
Hi,
What are you using for the current setting resistor?
Thanks
Salas,
what toroid would be preferable if I go for 1.2-1.5A version?
-80VA 2x15V
-100VA 2x12V
-100VA 2x17V
I would personally stay with 80VA toroid as it would be easier to install in the case I found.
Also would these outer heatsinks be enough for 1.5A version?
Tea-Bag,
got the board, thank you very much!
what toroid would be preferable if I go for 1.2-1.5A version?
-80VA 2x15V
-100VA 2x12V
-100VA 2x17V
I would personally stay with 80VA toroid as it would be easier to install in the case I found.
Also would these outer heatsinks be enough for 1.5A version?
Tea-Bag,
got the board, thank you very much!
not the 12Vac.
the 17Vac may require so much heatsinking that the chassis packaging becomes unmanageable.
That leaves you with the 80VA 15+15Vac. The maximum continuous output current is ~ 1.3Adc
You will be running the transformer at it's full maximum rating continuously if you draw 1.3Adc from the rectifiers.
You will be overloading the transformer if you draw 1.4Adc or 1.5Adc from that 80VA transformer.
If you really want 1.4A to 1.5A from the CCS Shunt regulator, then I recommend a 160VA to 200VA, 15+15Vac transformer and enormous heatsinks to dissipate the current loading.
the 17Vac may require so much heatsinking that the chassis packaging becomes unmanageable.
That leaves you with the 80VA 15+15Vac. The maximum continuous output current is ~ 1.3Adc
You will be running the transformer at it's full maximum rating continuously if you draw 1.3Adc from the rectifiers.
You will be overloading the transformer if you draw 1.4Adc or 1.5Adc from that 80VA transformer.
If you really want 1.4A to 1.5A from the CCS Shunt regulator, then I recommend a 160VA to 200VA, 15+15Vac transformer and enormous heatsinks to dissipate the current loading.
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From Salas:
Stage 0 = circa 75-85mA Ecological and cool. Smart car territory, the twin 47R 1W marked on the Blue and no or mini sinks will do.
Stage 1 = circa 200mA. Boosted enough, all purpose, some logical sinks. Standard Blue HR, Golf GTI territory. 4W dissipation per rail. 10R 5W.
Stage 2 = circa 600mA. Increased grip and pull back, Porsche stuff. 12W dissipation per rail. Sinks like for a 30W class A/B amp. 3R3 5W.
Stage 3 = circa 2A. No holds sense, Enzo feel. 40W dissipation per rail. F5 size sinks & Tx. 1R 12W.
Stage 0 = circa 75-85mA Ecological and cool. Smart car territory, the twin 47R 1W marked on the Blue and no or mini sinks will do.
Stage 1 = circa 200mA. Boosted enough, all purpose, some logical sinks. Standard Blue HR, Golf GTI territory. 4W dissipation per rail. 10R 5W.
Stage 2 = circa 600mA. Increased grip and pull back, Porsche stuff. 12W dissipation per rail. Sinks like for a 30W class A/B amp. 3R3 5W.
Stage 3 = circa 2A. No holds sense, Enzo feel. 40W dissipation per rail. F5 size sinks & Tx. 1R 12W.
AndrewT
thank you!
I've finished reading the whole thread and found that you've already adviced using a transformer for hot rod version not more than 50% of it's nominal, could you please eleborate a bit why is that? What could be the consequences except additional heat if I try to draw a currnet of 2A from 2.66A toroid?
I've already done several projects where I used encapsulated square and toroid transformers up to 85% of their nominal ampere rating. The only problem I found is the heat - it raises up to 50 c...
will the case be able to cope with heating if I go for 1.3A? I have found the calculation earlier in the thread but actually do not understand all the parameters there.
palmito
not sure what page but it was reported here that there is an improvement if you go for >=1A version, though it's not so noticeable as if you go from 200 to 600mA.
thank you!
I've finished reading the whole thread and found that you've already adviced using a transformer for hot rod version not more than 50% of it's nominal, could you please eleborate a bit why is that? What could be the consequences except additional heat if I try to draw a currnet of 2A from 2.66A toroid?
I've already done several projects where I used encapsulated square and toroid transformers up to 85% of their nominal ampere rating. The only problem I found is the heat - it raises up to 50 c...
will the case be able to cope with heating if I go for 1.3A? I have found the calculation earlier in the thread but actually do not understand all the parameters there.
palmito
not sure what page but it was reported here that there is an improvement if you go for >=1A version, though it's not so noticeable as if you go from 200 to 600mA.
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