One tastes like beef and the other tastes like chicken?
Has there been anyone who built both?
As far as filling in the missing numbers labelled as stash, ill do it. Working on BOM now. Trying to match my first AB100 amp as close as possible. And no I don't know what I did with that BOM. Anyway working on running two in bridged mode on some older Maggies. Planning on using balanced out from Self preamp.
In have one that I already finished about 6 months back. i listened to it off and on for about 2 weeks. I also have a HB amp also. Right now the HB is a better match for my speaker setup. I'm using very power hungry speakers Maggie IIc's. The AB is just a little under powered when i start turning up the sound. Therefore I'm looking at building another to match the first and using each as a monoblock. Not sure if that will be a problem because of the 6ohm load of the speaker. Each AB will see 3ohm load?? Not sure how it will handle that??
The centre connecting plate is a 3.2mm aluminum plate, it is just sprayed and + - is 2 mm copper strips.
Regards
I am just a clueless noob who wants to build a Nelson Pass amp.
The Tim Allen in me says bigger is always better, so 2mm thick and 2oz copper, but it costs more.
I don't know if more is better in this case and if it is worth the extra expense, or even if it has drawbacks (capacitance?).
From the little bit I have read about surface finished, ENIG should be the way to go.
There you have it, what I was going to go with based on a sample size of three.
I was looking to see if there were any dissenters or alternate opinions and weigh them against what I have read, before I ordered some boards.
David.
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Can you post more pictures of your finished amp?
What are some of the build details, like power supply specs, etc?
Thank you,
David.
Hi DaveFred,
The build is mostly as per NP's schematic. I used what I had around mostly. I didn't have 10,000 mF caps that fit on the amp board so I made a couple perf boards where the channels share the first 30,000uF on each rail then I put 2 x 6800uF per rail on the boards. The transformer is 500va with dual 35V secondaries. The common filter goes CRCRC with 10,000 - 0.25 Ohm -10,000 - 0.25 Ohm - 10,000. Like I said, I had these caps so I used them, I'm not saying they are needed or even helped.
The build is mostly as per NP's schematic. I used what I had around mostly. I didn't have 10,000 mF caps that fit on the amp board so I made a couple perf boards where the channels share the first 30,000uF on each rail then I put 2 x 6800uF per rail on the boards. The transformer is 500va with dual 35V secondaries. The common filter goes CRCRC with 10,000 - 0.25 Ohm -10,000 - 0.25 Ohm - 10,000. Like I said, I had these caps so I used them, I'm not saying they are needed or even helped.
I think this is the AB100,
Portal Audio Panache Integrated Amplifier
To me it looks like there was no "separate" capacitor bank, just the ones on the amp boards, fed by a dual output 425 VA toroidal transformer to two bridge rectifiers.
Original text,
-----
Why A Passive Preamp/High Gain Amp?
When we began to tackle the idea of a world-class, budget-priced integrated amp, the first ugly reality we faced was that you can't build an excellent-sounding active line stage on the cheap. Our answer was to build a passive line stage using the same level of parts you'll find in very high end preamps.
Although passive preamps are theoretically the most pure, many good free-standing designs just don't sound that good when connected to solid state amps. Most of them sound lifeless and lacking in dynamics. Reality is that the very high output impedance of the passive unit is being asked to drive the (generally) low input impedance of a solid state amp. Making the situation worse, is that the signal has to travel from preamp to amp over a length of reactive interconnect cable.
BUT...
What if you connected the output of this preamp directly to the input of a high-gain solid state amp designed expressly to receive that specific signal? That's the guiding design principle of the Portal Panache.
We're not claiming that the preamp section of this unit is perfect. It's just more perfect functionally than anything remotely in its price class. The input selector, balance control, and attenuator are Alps controls, each hand-selected for neutrality, lack of noise, and reliability. All point-to-point wiring - 14 gauge OFC with PE dielectric - is the shortest possible path. In other words, the signal only goes through the Alps controls and scant inches of pure copper before being delivered intact to the input of the amp.
Dual Mono Amplifier Section
The amplifier section is a dual mono design. The toroidal transformer, custom built for us in California, has separate windings and separate rectifier bridges for each channel. After the transformer, the two channels are completely separate, each with its own bank (40,000 MFD/ch) of filter capacitors, and each channel physically isolated to prevent interaction with its twin.
The transformer itself is rated at 425 va and is capable of producing twice its rated power for extended periods. With a potential 400 watts of power dissipation per channel - 4 pairs of high-speed bipolar output devices rated at 100 watts/12 amps per device - the rated 100 watts per channel into 8 ohms is very conservative. Operation is A/AB, with all stages before the output transistors operating in single-ended Class A mode.
MADE IN THE USA
To order call 1-888-737- HIFI
Description and Specifications
Click to Enlarge
The amp design is a classic complimentary symmetry A/AB design with a current source differential pair followed by a common emitter going to a Darlington configuration output stage.
Specifications:
Rated output: 100 watts/ch at 8 ohms;
200 watts/ch at 4 ohms
Click To EnlargeDistortion: 20 Hz-20kHz both ch driven
@ no more than 0.1% THD
Bandwidth:5 Hz to 100 kHz
Gain: 20 dB
Input impedance: 22 k Ohm
Slew rate: >20 v per microsecond
Specifications are subject to change without notice.
-----
Portal Audio Panache Integrated Amplifier
To me it looks like there was no "separate" capacitor bank, just the ones on the amp boards, fed by a dual output 425 VA toroidal transformer to two bridge rectifiers.
Original text,
-----
Why A Passive Preamp/High Gain Amp?
When we began to tackle the idea of a world-class, budget-priced integrated amp, the first ugly reality we faced was that you can't build an excellent-sounding active line stage on the cheap. Our answer was to build a passive line stage using the same level of parts you'll find in very high end preamps.
Although passive preamps are theoretically the most pure, many good free-standing designs just don't sound that good when connected to solid state amps. Most of them sound lifeless and lacking in dynamics. Reality is that the very high output impedance of the passive unit is being asked to drive the (generally) low input impedance of a solid state amp. Making the situation worse, is that the signal has to travel from preamp to amp over a length of reactive interconnect cable.
BUT...
What if you connected the output of this preamp directly to the input of a high-gain solid state amp designed expressly to receive that specific signal? That's the guiding design principle of the Portal Panache.
We're not claiming that the preamp section of this unit is perfect. It's just more perfect functionally than anything remotely in its price class. The input selector, balance control, and attenuator are Alps controls, each hand-selected for neutrality, lack of noise, and reliability. All point-to-point wiring - 14 gauge OFC with PE dielectric - is the shortest possible path. In other words, the signal only goes through the Alps controls and scant inches of pure copper before being delivered intact to the input of the amp.
Dual Mono Amplifier Section
The amplifier section is a dual mono design. The toroidal transformer, custom built for us in California, has separate windings and separate rectifier bridges for each channel. After the transformer, the two channels are completely separate, each with its own bank (40,000 MFD/ch) of filter capacitors, and each channel physically isolated to prevent interaction with its twin.
The transformer itself is rated at 425 va and is capable of producing twice its rated power for extended periods. With a potential 400 watts of power dissipation per channel - 4 pairs of high-speed bipolar output devices rated at 100 watts/12 amps per device - the rated 100 watts per channel into 8 ohms is very conservative. Operation is A/AB, with all stages before the output transistors operating in single-ended Class A mode.
MADE IN THE USA
To order call 1-888-737- HIFI
Description and Specifications
Click to Enlarge
The amp design is a classic complimentary symmetry A/AB design with a current source differential pair followed by a common emitter going to a Darlington configuration output stage.
Specifications:
Rated output: 100 watts/ch at 8 ohms;
200 watts/ch at 4 ohms
Click To EnlargeDistortion: 20 Hz-20kHz both ch driven
@ no more than 0.1% THD
Bandwidth:5 Hz to 100 kHz
Gain: 20 dB
Input impedance: 22 k Ohm
Slew rate: >20 v per microsecond
Specifications are subject to change without notice.
-----
And so the AB100 marches on.
Circuit originally designed for Nirvana Electronic Works:
Nirvana Electronic Works NEW A-60 Amplifier.WOOW | Audiogon Discussion Forum
After they went away, then used by Portal...
Portal Audio Panache integrated amplifier | Stereophile.com
Now diyAudio.
You will be amused to know that I have never made a nickel on it.
