My first post to this forum...been a lurker for a long time. After over 10 years of procrastination I decided to build out my dream system. I always wanted to build a line array speakers first then the Pass Labs power amp etc. After listening to my friend's IDS-25 speakers which really giving me confidence....I used the Murphy Corner Line Array design and built out the speakers. I did replace the drivers in the original design with the Vifa TG9FD10-08. The results were outstanding. I can post the details and pics of the construct separately if desired.
Long story short....The Pass Aleph 2 came in right after. Absolutely jaw dropping detail, presence, transparency and soundstage. I cant stop describing the superlatives. It's like listening to a live recordings while in studio. May still play with the bias a bit (less than 11mV DC offset). and replace the power supply configuration (may elaborate on a different thread)
Here lies the fundamental problem... After 20+ days of listening, testing the system I get my first electricity bill....O-U-C-H!!! Really! did not plan for this and its totally my fault. I work from home and have my system on all day streaming jazz radio or Spotify.
The question I have is ......can I with a switch cutoff half the output stage for normal background listening (save power) and only flip it full on when I do my late night listening or have friends over? Let's say I want to be green 😀 whiteout mentioning the current hole it will cause in my wallet. I don't want to change my listening habits either and definitely do not want to switch amps.
Credit to Mauro Forlani for providing the enclosure design Audiocostruzioni
The complete enclosure was manually milled (wish I had CNC)
cheers
Long story short....The Pass Aleph 2 came in right after. Absolutely jaw dropping detail, presence, transparency and soundstage. I cant stop describing the superlatives. It's like listening to a live recordings while in studio. May still play with the bias a bit (less than 11mV DC offset). and replace the power supply configuration (may elaborate on a different thread)
Here lies the fundamental problem... After 20+ days of listening, testing the system I get my first electricity bill....O-U-C-H!!! Really! did not plan for this and its totally my fault. I work from home and have my system on all day streaming jazz radio or Spotify.
The question I have is ......can I with a switch cutoff half the output stage for normal background listening (save power) and only flip it full on when I do my late night listening or have friends over? Let's say I want to be green 😀 whiteout mentioning the current hole it will cause in my wallet. I don't want to change my listening habits either and definitely do not want to switch amps.
Credit to Mauro Forlani for providing the enclosure design Audiocostruzioni
The complete enclosure was manually milled (wish I had CNC)
cheers
Attachments
The Aleph is not the best circuit for that idea because of it's single ended nature.
You will end up current clipping at bias settings below 1A.
You will end up current clipping at bias settings below 1A.
...build another amplifier (this is diyaudio after all!). Something class AB, or a chipamp maybe, or one of the class D builds, and make a switchbox to select which amp to use.
Seems a shame though! That's a lovely set of builds.
Seems a shame though! That's a lovely set of builds.
beautiful amps. but cant help you other than to suggest a class ab and switch box. Why not a low bias F5?
... install solar panels?
or turn amps of when not in use and change power companies🙂
Pass DIY Addict
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What a beautiful build! I have a pair of Aleph-2 boards kicking around that I toy with building from time to time... No doubt about it, 600w of continuous power burn is a big deal. In the winter, it helps keep the room warm. In the summer, it just creates competition with the air conditioning.
If you haven't replaced ALL of your lighting with LEDs, this can help offset things. Alternatively, pack up those energy sucking evil devices and mail them to me 🙂
If you haven't replaced ALL of your lighting with LEDs, this can help offset things. Alternatively, pack up those energy sucking evil devices and mail them to me 🙂
Haha...Thanks folks for your responses. Brought a smile to my face.
There is no going back here. However I do see the schematics for the Aleph 5 and 2 are almost identical except for the bias and output stages. My thought was that can I offload these to a separate board and call it "configuration board" and very easily switch from Aleph 2 to Aleph 5? 300W in savings will help 🙂
I could use high quality gold plated jumper sets or even use a bank of relays (w/gold contacts) with a single switch to toggle between the two configurations? Not sure If I'll need to do anything major with the PSU?
I know many of you may poopoo the concept of introducing relays etc. in the signal path....and my sentiments are similar.
Either mechanism could be easily accommodated on the back panel or under the covers without impacting the visuals.
Your thoughts.....
There is no going back here. However I do see the schematics for the Aleph 5 and 2 are almost identical except for the bias and output stages. My thought was that can I offload these to a separate board and call it "configuration board" and very easily switch from Aleph 2 to Aleph 5? 300W in savings will help 🙂
I could use high quality gold plated jumper sets or even use a bank of relays (w/gold contacts) with a single switch to toggle between the two configurations? Not sure If I'll need to do anything major with the PSU?
I know many of you may poopoo the concept of introducing relays etc. in the signal path....and my sentiments are similar.
Either mechanism could be easily accommodated on the back panel or under the covers without impacting the visuals.
Your thoughts.....
I'm not intrinsically against any of those things...
Thinking aloud here, but if you've a transformer with split primaries, you could have a selector switch that wires the transformer for 120/240V operation, thus halving the voltages on the rails when in 240V mode. That's about the cleanest solution I can think of.
Thinking aloud here, but if you've a transformer with split primaries, you could have a selector switch that wires the transformer for 120/240V operation, thus halving the voltages on the rails when in 240V mode. That's about the cleanest solution I can think of.
Replace your power transformers with ones that have dual secondaries. You can have switchable secondaries so you have both +/-45Vdc for Aleph 2 and Aleph 5 +/-35Vdc supplies.
Pass DIY Addict
Joined 2000
Paid Member
Now THAT's an elegant solution. There are two possible solutions: changing rail voltage and changing bias current. I was trying to think of a simple way to change bias, but I like this suggestion for the transformer better.
Aaaah...Less is more! The KISS (Keep It Simple Stupid) principle. Yes the toroids are dual primary....and I have one unit open to the reconfigure the PSU board. Easy enough to test. Thanks Aspringv and Blues! I will try this out soon(hopefully) and post. The cost of 1 switch and an extra Thermistor is so minimal 🙂.....or maybe a pair of lightly used 750VA yoroids may show up for sale.
its been 30 years since i last dabbled in electronics, built amps etc. and this was and is so much fun. Life gets in the way.
btw on another note......if you own a pair of nice speakers and an Pass aleph...do crank up Muddy Waters "Folk Singer" ...or Miles Davis "Assenseur pour L'echafaud" ...or Diana Krall's "A Case of You" live in Paris........absolutely transcending....
My apologies for being all over the map 🙂
...and if you ever move country you'll be all good as well!
I'd maybe wait for another member or two to chip in on that idea. I'm no guru, but I can't see any reason it wouldn't work.
I'd maybe wait for another member or two to chip in on that idea. I'm no guru, but I can't see any reason it wouldn't work.
If you like the sound of the Aleph, then you like the harmonic signature of SE Class A amps, dominant 2nd harmonic, lower third harmonic, not much else. Try the Ranchu Aksa Quasi Class AB amp. It has the same harmonic structure (Hugh designed it to mimic a SE Class A amp). It runs 120mA bias from +/-35v supplies and is much more green.
The Dacz layout is proven and tested. Great sounding amp.
http://www.diyaudio.com/forums/soli...mentary-mosfet-amplifier-197.html#post5172427
The Dacz layout is proven and tested. Great sounding amp.
http://www.diyaudio.com/forums/soli...mentary-mosfet-amplifier-197.html#post5172427
Looks like the primary switching is a go-er. Feeding 120V to a transformer configured for 240V?
Edit : and thanks for the musical suggestions - I've an aleph 2 ish clone at home, so I'll get amongst your suggestions. 🙂
Edit : and thanks for the musical suggestions - I've an aleph 2 ish clone at home, so I'll get amongst your suggestions. 🙂
I recently had some transformers custom made like this, but there are multiple taps on the secondaries.
before doing anything with rails , make a test with variac
I'm pretty sure that you're going to have troubles with DC offset at output
I'm pretty sure that you're going to have troubles with DC offset at output
A totally different way to save a lot of energy would be to switch on and off the amp using a 'music sensor' circuit like Martin Logan uses f.ex.
If you adjust the bias current and/or rail voltages of the Aleph, you will also
need to adjust the DC offset at the output.
need to adjust the DC offset at the output.
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