fcel said:
This design shows asymmetric banks of caps before and after the
inductors... others show symmetric banks (same capacity) with
inductors in between... still others use more caps after the inductors than ahead.
Suppose that more capacity ahead helps to achive a voltage closer to the same
supply without inductors... but why then don't just use symmetric banks? 😕
Peter ... ask your utility to change out the transformer on the pole outside your window ... tell them that it affects the quality of your sound system ... actually you have to lie ...
Marijan ... I don't remember the exact story now but weren't you having "crack" thermister in your Aleph 2's .... could it be due to those huge capacitor bank, 1.5KVA transformer and $4 bridge diodes? No offense!
By the way, Wayne Shorter is a Jazz artist. You were in fact referring to Wayne Sanskey.
Marijan ... I don't remember the exact story now but weren't you having "crack" thermister in your Aleph 2's .... could it be due to those huge capacitor bank, 1.5KVA transformer and $4 bridge diodes? No offense!
By the way, Wayne Shorter is a Jazz artist. You were in fact referring to Wayne Sanskey.
Thermistor cracked because the amp was switched on twice in a short time period and it didnt cooled down..
What is the max voltage that aleph 2 can be fed with?
What is the max voltage that aleph 2 can be fed with?
fcel said:
There is actually a transformer in front of my window. They put it there last year. I thought it would be beneficial, you know the shorter wires and all....😉
Voltage Drop
Just for some fun discussion here ...
If the Utility could relocate the overhead transformer (I'm assuming it's feeding your house too) a couple poles away ... just so that it'll get that certain amount of voltage drop .... then you'll have your 120v at your wall outlet ... but then in Summer time with all the air conditioning on in every house, you'll end up with inadequate voltage ... may be it's time for UPS power!
Just for some fun discussion here ...
If the Utility could relocate the overhead transformer (I'm assuming it's feeding your house too) a couple poles away ... just so that it'll get that certain amount of voltage drop .... then you'll have your 120v at your wall outlet ... but then in Summer time with all the air conditioning on in every house, you'll end up with inadequate voltage ... may be it's time for UPS power!
Ha,ha,ha!
Wayne Sankey sory! I supouse it was Shorter`s CD on my desk while writeing my mesage. Lapsus lingue.
Cool down period of thermistor was a posible reason for broken thermistor on ground earth rail. Real reason was much more stupid and it was absolutly my constructing mistake. My toroid was mounted to close to the chasis bars and during vibrations...
I had a shortcut betwin toroid winding and earth, which is conected to 0 point via thermistor.
Lucky my. Nothing broken.
Mybe I could start a thread " My most stupid mistake"
Wayne Sankey sory! I supouse it was Shorter`s CD on my desk while writeing my mesage. Lapsus lingue.
Cool down period of thermistor was a posible reason for broken thermistor on ground earth rail. Real reason was much more stupid and it was absolutly my constructing mistake. My toroid was mounted to close to the chasis bars and during vibrations...
I had a shortcut betwin toroid winding and earth, which is conected to 0 point via thermistor.
Lucky my. Nothing broken.
Mybe I could start a thread " My most stupid mistake"
Since the discussion has centered heatsinks I thought I would show off the beginning of a "Virtual" Aleph 2. The design is based on the MM11645 heatsink profile and the Plitron 1.5KVA x-former. Obviously, my virtual amp still has a way to go before I can play virtual SACD's through some virtual speakers.
One advantage of building components in the virtual domain is that I won't have to worry about heat dissipation. However, I have been having trouble rendering my ears into this environment and fear I may have to actually build a pair of physical Aleph 2's to satisfy my needs.
Much too late for rational thought,
Chris
One advantage of building components in the virtual domain is that I won't have to worry about heat dissipation. However, I have been having trouble rendering my ears into this environment and fear I may have to actually build a pair of physical Aleph 2's to satisfy my needs.
Much too late for rational thought,
Chris
Attachments
hi cbcassell,
just wondering what u use to draw these pics?
Im also ready to order some transformers now that Ive found an almost local geting source. The company is Harbuch electronics and they make toroidal Txs under license to Antrim. Has anyone heard of either of theses companies and what to look for in transformers, my only real fear is hum as Ive read that they can cause problems. Should I go for it and pocket a couple of hundred dollars or is it worth getting a known brand?
Also been unsure about voltage too as Ive read people state that 1.2 X is actual rail voltage, but 40v x 1.2 is 48 volts as required, Ive seen designs using everything from 33 to 40? Should I not worry too much and just order?
just wondering what u use to draw these pics?
Im also ready to order some transformers now that Ive found an almost local geting source. The company is Harbuch electronics and they make toroidal Txs under license to Antrim. Has anyone heard of either of theses companies and what to look for in transformers, my only real fear is hum as Ive read that they can cause problems. Should I go for it and pocket a couple of hundred dollars or is it worth getting a known brand?
Also been unsure about voltage too as Ive read people state that 1.2 X is actual rail voltage, but 40v x 1.2 is 48 volts as required, Ive seen designs using everything from 33 to 40? Should I not worry too much and just order?
Antrim Transformers
This company is well respected here in UK. They produce custom designs and have audio "specials" - Prices are competitive.
Not really sure that you can ask for more!!
This company is well respected here in UK. They produce custom designs and have audio "specials" - Prices are competitive.
Not really sure that you can ask for more!!
That virtual Aleph looks wider than Wayne's amp.
I liked the narrow profile, but will confess that fitting the
Victoria Magnetic's transformer and 4 Mallory's in bottom
took up ALL of the room.
I would have made my chassis wider if I were starting over.
I liked the narrow profile, but will confess that fitting the
Victoria Magnetic's transformer and 4 Mallory's in bottom
took up ALL of the room.
I would have made my chassis wider if I were starting over.
Why don't you place your transformer vertically or mount capacitors above transformer. It's a bit more work but looks way better.
Hi,
The model was created in Vectorworks.
I have not fixed the dimensions as yet. The power supply real estate is not allocated. Obviously, the majority of the interior of the chassis will be power supply and this and the heatsinks determines the final dimensions.
One advantage to teaching is that I can get cheap brain power. I gave my intern the assignment to calculate the size of a heatsink to dissipate to heat load from the MOSFETs in the Aleph 2. Using the MM11645 profile, the minimum size is about 35 linear inches of heatsink. I still have to double check the student's equations and calculations, but based on visuals of Nelson's Aleph and various diy Alephs he is not too far off the mark.
Before building a power supply, I would recommend perusing the Duncan PSU II freeware program. It is mentioned by several others in the forum. I have found it enlightening. As far as the measurement values that PSU II displays, they seem to correspond to real world values. I would have to defer to those on this site with far greater experience and would appreciate their feedback as to the validity of those numbers.
Since I have yet to build one of these projects, I am still a babe in the woods.
However, I have been around long enough to appreciate the "tech" humor of an amplifier designer who rates his amplifiers in horsepower.
Chris
The model was created in Vectorworks.
I have not fixed the dimensions as yet. The power supply real estate is not allocated. Obviously, the majority of the interior of the chassis will be power supply and this and the heatsinks determines the final dimensions.
One advantage to teaching is that I can get cheap brain power. I gave my intern the assignment to calculate the size of a heatsink to dissipate to heat load from the MOSFETs in the Aleph 2. Using the MM11645 profile, the minimum size is about 35 linear inches of heatsink. I still have to double check the student's equations and calculations, but based on visuals of Nelson's Aleph and various diy Alephs he is not too far off the mark.
Before building a power supply, I would recommend perusing the Duncan PSU II freeware program. It is mentioned by several others in the forum. I have found it enlightening. As far as the measurement values that PSU II displays, they seem to correspond to real world values. I would have to defer to those on this site with far greater experience and would appreciate their feedback as to the validity of those numbers.
Since I have yet to build one of these projects, I am still a babe in the woods.
However, I have been around long enough to appreciate the "tech" humor of an amplifier designer who rates his amplifiers in horsepower.
Chris
Calc
Can you "publish" your intern's calculation here to show exactly how it's calculated? May be start a new thread. Sizing heatsink is the most often asked questions on this thread. If there is a "go-by", everybody will know what data to collect and what formula to use to calculate the size of heatsinks.
Can you "publish" your intern's calculation here to show exactly how it's calculated? May be start a new thread. Sizing heatsink is the most often asked questions on this thread. If there is a "go-by", everybody will know what data to collect and what formula to use to calculate the size of heatsinks.
Getting back on line with the topic here I am still in the process of gathering some of the last parts I need to build my Aleph2c's. Have the PCB's from Gary GT all assembled, all transistors matched, power supply caps. The heatsinks ordered form M&M Metals. Will start on the chassis when the sinks arrive.........
When it comes to transformers for this amp I have two choices. The first being a surplus toroid that I bought locally for 5 bucks each. It is a UVELCO 769VA unit with a 29-0-29 volt secondary. This toroid seems a bit on the low voltage range for an Aleph 2. I can also order two new toroids from Avel Lindberg at a reasonable price, 80 dollars each, for a 1KVA transformer. They have both 35-0-35, and 40-0-40 volt secondary transformers available. Using 1.2 as the factor on these the 35 volt would give me plus and minus 42 volts, and the 40 volt unit would give me plus and minus 48, which would you guys use?
Mark
When it comes to transformers for this amp I have two choices. The first being a surplus toroid that I bought locally for 5 bucks each. It is a UVELCO 769VA unit with a 29-0-29 volt secondary. This toroid seems a bit on the low voltage range for an Aleph 2. I can also order two new toroids from Avel Lindberg at a reasonable price, 80 dollars each, for a 1KVA transformer. They have both 35-0-35, and 40-0-40 volt secondary transformers available. Using 1.2 as the factor on these the 35 volt would give me plus and minus 42 volts, and the 40 volt unit would give me plus and minus 48, which would you guys use?
Mark
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