agree
and use some cheap spks while testing, that's common practice
when you have speakers you're happy with, that's your biggest treasure ..... everything else can be repaired, less or more easy, but speakers are ........... especially if you adore some ultrarare Drek (my case exactly)
and use some cheap spks while testing, that's common practice
when you have speakers you're happy with, that's your biggest treasure ..... everything else can be repaired, less or more easy, but speakers are ........... especially if you adore some ultrarare Drek (my case exactly)
That tweeter's like 20 bucks a pair so whatever and, you are right Zen Mod, it's the Goodmans that are the treasure. Any chance someone tell me, is there a flaw in my calculations? 15 ohm Goodmans Axiom 201 full range run without a crossover and 4-8 Ohm Pyle Pro PDBT19 on a 3.3 µF, anything porblematic here? Perhaps the difference between 15 Ohm and 4-8 Ohm is the culprit?
[edit: now I really don't know how to post a formula, do I/]
1 ________________ | |||
| fc= | 2π×4×3.3×10−61 | ≈12,070Hz |
[edit: now I really don't know how to post a formula, do I/]
don't bother with calculus too much
start with 1uF and increase by 0.47uF
when too much, go back one step
if needed insert ohm-2-3 in series if there is nice blending but little hot
start with 1uF and increase by 0.47uF
when too much, go back one step
if needed insert ohm-2-3 in series if there is nice blending but little hot
Wanted to thank you all for your recommendations! I just connected my newly arrived Khozmo (resistance 10, 64step shunt AMRG Vishay) to the Pass ACAs and I am hypnotised glued to the speakers. Don't Get Me started / The Smile playing now and I can almost see the palms of the drummer's hands.
I think this goes to show how seriously good of an amp is a pair of Pass ACAs. Back to matching them with a Khozmo, others have written about detail and transparency. My first shock is that I started understanding the lyrics of some songs that I thought are just mumbled "by nature" - I hear and discern each word now. Channel separation is better too (as it should be, running the ACA as "monoblocks"). The other surprize is that this resolution is present already at very low levels.
At the same time I can already anticipate what might be the first future impulse to continue the upgrade madness: it's the somewhat hyper-atmospheric presentation with precise but juuuuust slightly shy bass. Just how (and if) will I approach this - I have no idea, as probably adding bass can be done with a B1 (but is there a reasonable balanced version)? Or perhaps a digital DSP (but where does the madness stop)?
Anyway - for now just a big thank you for your reccomendations and I'm back to listening!
I think this goes to show how seriously good of an amp is a pair of Pass ACAs. Back to matching them with a Khozmo, others have written about detail and transparency. My first shock is that I started understanding the lyrics of some songs that I thought are just mumbled "by nature" - I hear and discern each word now. Channel separation is better too (as it should be, running the ACA as "monoblocks"). The other surprize is that this resolution is present already at very low levels.
At the same time I can already anticipate what might be the first future impulse to continue the upgrade madness: it's the somewhat hyper-atmospheric presentation with precise but juuuuust slightly shy bass. Just how (and if) will I approach this - I have no idea, as probably adding bass can be done with a B1 (but is there a reasonable balanced version)? Or perhaps a digital DSP (but where does the madness stop)?
Anyway - for now just a big thank you for your reccomendations and I'm back to listening!
So I am back for a second kick at the can on another ACA amp, and I have to say that the second time around makes a LOT more sense -- although I imagine I will mess something up.
Unfortunately, my kit did not come with the "wire bag" and I do not have enough of the 22ga wire left over from the last build. Is there a particular kind of wire recommended for the red between the power input and the power button? On Amazon there seems to be two kinds of 22ga wire: strands and a solid wire. What kind of wire was the kit supposed to have? Like would this work?
Thanks!
Unfortunately, my kit did not come with the "wire bag" and I do not have enough of the 22ga wire left over from the last build. Is there a particular kind of wire recommended for the red between the power input and the power button? On Amazon there seems to be two kinds of 22ga wire: strands and a solid wire. What kind of wire was the kit supposed to have? Like would this work?
Thanks!
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Personally, I like stranded wire BUT it is difficult to keep it tightly twisted without additional work. Solid core twists well and stays that way but it is more likely (in my experience) to experience fatigue and cracking/breaking if handled frequently through periodic redressing and relocating of wires.
The central run from power Jack to front panel switch, however, should not be moving and being redressed more than once or twice. So that is where solid core is best used, IF you are going to use it.
I personally like Teflon insulated for soldering heat resistance, but others have different opinion.
I express no opinion on sonic difference between stranded versus solid core wire.
The central run from power Jack to front panel switch, however, should not be moving and being redressed more than once or twice. So that is where solid core is best used, IF you are going to use it.
I personally like Teflon insulated for soldering heat resistance, but others have different opinion.
I express no opinion on sonic difference between stranded versus solid core wire.
Did you contact the store to request a wire bag? They have always been great about things like that in my experience.
Oh I did reach out to the store and I am sure they will help out, I just figured I should have some extra wire lying around for cases like this regardless.
And if they cannot for some reason then I can go ahead and finish.
What Halauhula made a lot of sense about solid versus strands for structure and twists.
Thanks everyone.
And if they cannot for some reason then I can go ahead and finish.
What Halauhula made a lot of sense about solid versus strands for structure and twists.
Thanks everyone.
I completed my second ACA amp so that I could run them as mono blocks into my Heresy IV speakers. Whew...a whole lot easier the second time round thanks to everything this group taught me when the first one went awry. I made sure to be more careful with my soldering, used the Cardas solder from DIY, and got the whole thing up and running in just a few careful afternoon sessions.
Some initial general thoughts for anyone wanting to try this out. 1) I prefer the mono blocks with my set up. The power just feels more clear and the soundstage has separation in a really cool distance.
2) The clarity of the bass is noticeable moving from one to the other. Before ACA, bass was thick, with one amp it was thin but more responsive. With two blocks, the bass on tracks like Sade's "Smooth Operator" sounds like a real bass in attack and range.
3) Burn in is a real thing on these amps. I notice a huge improvement after about 2 hours of run time, especially between the new amp and the one that had a few hundred hours on it already. Just do not be disappointed if the initial sound is not ideal. Let it run and wait for a change.
4) For me, these are my endgame amps. I do not listen to loud volumes and this is probably the best I can afford or justify. I really love that I assembled them myself and they give me an "audiophile" sound without further obsession into snake oil or heavy investment. I will finish building my Bottlehead Moreplay next week and that should give me a less clinical sound compared to the preamplifier of the AudioLab 6000a run in pre mode. I know that my Peachtree Nova sounded closer to what I finally want, but I think the tube preamplifier will balance nicely into the ACA class a solid state.
Anyway, lots of learning here and great fun. Thanks for all of the help along the way with the first iteration.
A.
Some initial general thoughts for anyone wanting to try this out. 1) I prefer the mono blocks with my set up. The power just feels more clear and the soundstage has separation in a really cool distance.
2) The clarity of the bass is noticeable moving from one to the other. Before ACA, bass was thick, with one amp it was thin but more responsive. With two blocks, the bass on tracks like Sade's "Smooth Operator" sounds like a real bass in attack and range.
3) Burn in is a real thing on these amps. I notice a huge improvement after about 2 hours of run time, especially between the new amp and the one that had a few hundred hours on it already. Just do not be disappointed if the initial sound is not ideal. Let it run and wait for a change.
4) For me, these are my endgame amps. I do not listen to loud volumes and this is probably the best I can afford or justify. I really love that I assembled them myself and they give me an "audiophile" sound without further obsession into snake oil or heavy investment. I will finish building my Bottlehead Moreplay next week and that should give me a less clinical sound compared to the preamplifier of the AudioLab 6000a run in pre mode. I know that my Peachtree Nova sounded closer to what I finally want, but I think the tube preamplifier will balance nicely into the ACA class a solid state.
Anyway, lots of learning here and great fun. Thanks for all of the help along the way with the first iteration.
A.
@anthonynchandler Woo HOO! Can't wait to hear your thoughts once the Bottlehead is up and running. What mono mode are you using?
Ahhh, now that you mention mono mode, I just realized that there are two. I thought the second option was for XLR. I was using bridge mode, I think. I will have to build some jumper cables to try out parallel mode tomorrow. Can probably finish the Bottlehead preamp in a week of spare time, but I am enjoying the two amps in mono well enough. Took the sounds to a different place that works better for my room.
@anthonynchandler
my understanding is that bridging or paralleling would increase power and decrease distortion so... I modified my build plans to include a balanced BA2018 to accept balanced inputs from a DAC and a Pearl 3.
I chose the ACA Redux version for the looks.
my understanding is that bridging or paralleling would increase power and decrease distortion so... I modified my build plans to include a balanced BA2018 to accept balanced inputs from a DAC and a Pearl 3.
I chose the ACA Redux version for the looks.
If you have a recent build, there are three ready-made mono modes.
Congrats on your ACAs? What version(s) did you build?
Updates.
Last night, I just finished completing the build of the Bottlehead Moreplay. As with my first ACA build, I had a few issues that took some time to troubleshoot, but like this group, I was given significant support and learned all kinds of things about signal tracing and how to use my multimeter.
Initially I thought I had made a huge mistake by adding the Moreplay to the system as everything sounded fuzzy and clipped, but then I realized that the 6n6 NOS tubes which were from Soviet times had not even warmed up. Right off the bat I have to say that with the Pass ACA as mono blocks, the preamplifier completely changes the character of what the amplifiers offer up in sound. With the Audiolab 6000A as a preamplifier, the ACA sound clear but restrained and definitely limited by the wattage. Still, it felt controlled and what "hi-fi" might sound like if I visited a local dealer: transparent, but responsive. Bass was thin, but the attack was defined on songs my Sade (FLAC rip on Roon server or Steely Dan (UHQR Vinyl).
Putting the warmed up Moreplay into the chain, suddenly makes the ACA sound less restrained, more bass present, thicker. The vocals become almost uncomfortable in their presence. The singer's voice takes over centre stage when listening to Johnny Cash's American series. The soundstage is more concentrated as if in a cafe performance rather than a studio recording. The bass become less controlled, but thicker and more late 70s, early 80s in presentation. I did find it initially challenging to understand how to manage the clipping created by running the Moreplay too loudly. I am probably only able to use a small amount of the Moreplay's gain (1/3) but the highs clips into distortion. But then taking it down to a softer listening level (75db) takes the clipping away, and then softer (60db) makes it much more listenable. Because of the thick soundstage of the Moreplay, which is congested in the higher ranges of volume, I feel like this set up is best for music that benefits from this type of intimacy. Again, something like AC/DC sounds like it is in a small club rather than a stadium, which can become a little fatiguing to the ears over a longer period of time.
Overall, I think that the greatest benefit of this entire build process has been learning about how different components affect each other, their role in the chain, my actual sound preference versus audiophile wisdoms, and then a consideration of what the value of of owning pieces that I personally assembled instead of going to a shop and telling someone else to assemble a system for me.
One thing I do need to admit is that while troubleshooting the Moreplay I accidentally inserted just my iPhone directly into one of the ACA amps through a U circuit in the outputs (both the output and input were attached to the outputs, so it was a flow though), and the iPhone directly into the single ACA gave a shockingly good sound with soundstage separation and all of the other areas. It did feel strained and not what I would always want, but it was pretty awesome for what it was.
Based on today's subjective testing, I feel like I will want to keep the Audiolab 6000A as power amp and the ACA mono block configurations as two options that I can switch between by maybe using a speaker switch. I think the Moreplay circuit and tubes will burn in over time, and a few things that it offers are kind of valuable in my situation of a smaller living room: balance controls for the speakers and two outputs. By adding a Schitt SYS switch on one output I am able to connect by Bottlehead Crack to the output, switch between the ACAs and the Crack AND attenuate the output of the Moreplay so that it does not send all of its gain to the Crack. The volume on the SYS is normal level at full, and lowering it attenuates the signal to a useable level.
So yeah...overall, I am happy with the whole process of this year's builds and I feel like this is probably the best system I can afford financially while accepting the room/lifestyle limitations I have. My ideal of sound is probably the sound of a childhood interpretation of a tubey all in one stereo console with cheap vinyl veneer and an 8 track, record player and an early CD player hooked into the back of it. While it might be nice to have a full McIntosh system through some Klipsch Cornwalls, this feels more authentic to me as a person and that does matter in our ever crazy world where nothing ever seems good enough. Again, thanks to those who helped me with the ACA builds. Going through the troubleshooting process due my my errors was far more valuable to me than simply being able to flawlessly build without soldering mistakes and boring up two transistors. Below I will list the system components:
Klipsch Heresy IV speakers
Audiolab 6000a Integrated Amplifier
Audiolab 6000CDT
Project Debut III Carbon with Ortofon Blue cartridge and Acryl-It platter
Pro-Ject Tube Box Phone Preamp
Raspberry Pi3 as a Roon Endpoint into a Topping D10s DAC
Two Pass ACA amplifiers as Parallel Mono Blocks
Bottlehead Moreplay
Bottlehead Crack with Speedball Upgrade
Sennheiser HD 6XX headphones
Audeze LCD-X headphones
Audioquest Tower, Evergreen, Golden Gate cables
Last night, I just finished completing the build of the Bottlehead Moreplay. As with my first ACA build, I had a few issues that took some time to troubleshoot, but like this group, I was given significant support and learned all kinds of things about signal tracing and how to use my multimeter.
Initially I thought I had made a huge mistake by adding the Moreplay to the system as everything sounded fuzzy and clipped, but then I realized that the 6n6 NOS tubes which were from Soviet times had not even warmed up. Right off the bat I have to say that with the Pass ACA as mono blocks, the preamplifier completely changes the character of what the amplifiers offer up in sound. With the Audiolab 6000A as a preamplifier, the ACA sound clear but restrained and definitely limited by the wattage. Still, it felt controlled and what "hi-fi" might sound like if I visited a local dealer: transparent, but responsive. Bass was thin, but the attack was defined on songs my Sade (FLAC rip on Roon server or Steely Dan (UHQR Vinyl).
Putting the warmed up Moreplay into the chain, suddenly makes the ACA sound less restrained, more bass present, thicker. The vocals become almost uncomfortable in their presence. The singer's voice takes over centre stage when listening to Johnny Cash's American series. The soundstage is more concentrated as if in a cafe performance rather than a studio recording. The bass become less controlled, but thicker and more late 70s, early 80s in presentation. I did find it initially challenging to understand how to manage the clipping created by running the Moreplay too loudly. I am probably only able to use a small amount of the Moreplay's gain (1/3) but the highs clips into distortion. But then taking it down to a softer listening level (75db) takes the clipping away, and then softer (60db) makes it much more listenable. Because of the thick soundstage of the Moreplay, which is congested in the higher ranges of volume, I feel like this set up is best for music that benefits from this type of intimacy. Again, something like AC/DC sounds like it is in a small club rather than a stadium, which can become a little fatiguing to the ears over a longer period of time.
Overall, I think that the greatest benefit of this entire build process has been learning about how different components affect each other, their role in the chain, my actual sound preference versus audiophile wisdoms, and then a consideration of what the value of of owning pieces that I personally assembled instead of going to a shop and telling someone else to assemble a system for me.
One thing I do need to admit is that while troubleshooting the Moreplay I accidentally inserted just my iPhone directly into one of the ACA amps through a U circuit in the outputs (both the output and input were attached to the outputs, so it was a flow though), and the iPhone directly into the single ACA gave a shockingly good sound with soundstage separation and all of the other areas. It did feel strained and not what I would always want, but it was pretty awesome for what it was.
Based on today's subjective testing, I feel like I will want to keep the Audiolab 6000A as power amp and the ACA mono block configurations as two options that I can switch between by maybe using a speaker switch. I think the Moreplay circuit and tubes will burn in over time, and a few things that it offers are kind of valuable in my situation of a smaller living room: balance controls for the speakers and two outputs. By adding a Schitt SYS switch on one output I am able to connect by Bottlehead Crack to the output, switch between the ACAs and the Crack AND attenuate the output of the Moreplay so that it does not send all of its gain to the Crack. The volume on the SYS is normal level at full, and lowering it attenuates the signal to a useable level.
So yeah...overall, I am happy with the whole process of this year's builds and I feel like this is probably the best system I can afford financially while accepting the room/lifestyle limitations I have. My ideal of sound is probably the sound of a childhood interpretation of a tubey all in one stereo console with cheap vinyl veneer and an 8 track, record player and an early CD player hooked into the back of it. While it might be nice to have a full McIntosh system through some Klipsch Cornwalls, this feels more authentic to me as a person and that does matter in our ever crazy world where nothing ever seems good enough. Again, thanks to those who helped me with the ACA builds. Going through the troubleshooting process due my my errors was far more valuable to me than simply being able to flawlessly build without soldering mistakes and boring up two transistors. Below I will list the system components:
Klipsch Heresy IV speakers
Audiolab 6000a Integrated Amplifier
Audiolab 6000CDT
Project Debut III Carbon with Ortofon Blue cartridge and Acryl-It platter
Pro-Ject Tube Box Phone Preamp
Raspberry Pi3 as a Roon Endpoint into a Topping D10s DAC
Two Pass ACA amplifiers as Parallel Mono Blocks
Bottlehead Moreplay
Bottlehead Crack with Speedball Upgrade
Sennheiser HD 6XX headphones
Audeze LCD-X headphones
Audioquest Tower, Evergreen, Golden Gate cables
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My best listening experiences have been in small clubs. Well... that's where the good music was playing. (aside from the symphony)
And I would have loved to have been able to hear the Rolling Stones at the El Mocombo in Toronto when I was a kid.
Funnily enough, I took you up on that idea, plopped a recording of that concert with its f4 dynamic range and it sounds pretty awesome on this setup - ha ha ha.
Actually, I ran through a few small club recordings (Stones at Checkerboard Lounge, Wynton Marsalis at the House of Tribes, Live at the Pawn Shop), and this may be the ideal "soundstage for this particular combo, as it feels like a 20x20 stage.
Actually, I ran through a few small club recordings (Stones at Checkerboard Lounge, Wynton Marsalis at the House of Tribes, Live at the Pawn Shop), and this may be the ideal "soundstage for this particular combo, as it feels like a 20x20 stage.