Thanks Tony.
The position of all parts is right, I have checked it twice.
I don't have a scope and a signal generator, but I could work with them. Sadly, in the last 30 years I had nothing to do with electrotechnics (practically), altough I am an electrical engineer and studied electrical engineering (no amps, it was production technology of electrical components), my thesis was a self-designed active 3-way crossover, but then live has changed...
Yesterday I had 2 hours for listening and the caps were just constant warm, but not hot. It could be the temperature which is high there in the amp.
The amp is great
The position of all parts is right, I have checked it twice.
I don't have a scope and a signal generator, but I could work with them. Sadly, in the last 30 years I had nothing to do with electrotechnics (practically), altough I am an electrical engineer and studied electrical engineering (no amps, it was production technology of electrical components), my thesis was a self-designed active 3-way crossover, but then live has changed...
Yesterday I had 2 hours for listening and the caps were just constant warm, but not hot. It could be the temperature which is high there in the amp.
The amp is great
Does anyone use a single ACA to power Klipsch RP-600M bookshelf speakers? These are rated at 96 dB sensitivity, but I can crank up the volume to 100% (PS Audio DAC w/ volume) and I doubt I'll get any noise complaints. It is perfectly clear and distortion-less at 100% volume too, which is amazing, but also not very loud
Also noteworthy is that my DAC only pushes out 1.4V to the RCA outs that feed into the ACA.
I don't believe anything is wrong with my ACA, I'm just curious as to what other people are experiencing with the Klipsch RP-600M + ACA combo.
Also noteworthy is that my DAC only pushes out 1.4V to the RCA outs that feed into the ACA.
I don't believe anything is wrong with my ACA, I'm just curious as to what other people are experiencing with the Klipsch RP-600M + ACA combo.
Hello!
New day, new listening session After one hour I adjusted the DC balance again, to 12,04V for both channels.
My preamp (a Project StreamBox RS with tube) can deliver 1V only, so I can listen at normal volumes, but not really loud with my Sonus Faber Venere 2.5. Normally I use a Copland CSA-28 integrated amp (or a Rega Elicit-R, but I don't like it anymore).
My first impression is, that the mids are gorgeous. Allan Taylor or Josh Kelley are just standing in front of me, great. The voice of Amy Duncan comes with all the facets very live-like. The bass is deep and "black" if that makes sense The amp offers a wide and deep and open soundstage, the instruments are well placed with air between them, so one can imagine and "hear" the stage eyes closed The highs are "sweet", maybe a little underemphasized but for this not tiring.
So... as the President said in "Independence Day", "not bad, not bad at all..." In fact, it is a great amp. Even when compared with the Copland.
Hopefully I can finish the second amp next week so I can use them bridged @15w.
Cheers
New day, new listening session
After one hour I adjusted the DC balance again, to 12,04V for both channels. My preamp (a Project StreamBox RS with tube) can deliver 1V only, so I can listen at normal volumes, but not really loud with my Sonus Faber Venere 2.5. Normally I use a Copland CSA-28 integrated amp (or a Rega Elicit-R, but I don't like it anymore).
My first impression is, that the mids are gorgeous. Allan Taylor or Josh Kelley are just standing in front of me, great. The voice of Amy Duncan comes with all the facets very live-like. The bass is deep and "black" if that makes sense
The amp offers a wide and deep and open soundstage, the instruments are well placed with air between them, so one can imagine and "hear" the stage eyes closed The highs are "sweet", maybe a little underemphasized but for this not tiring. So... as the President said in "Independence Day", "not bad, not bad at all..."
In fact, it is a great amp. Even when compared with the Copland.Hopefully I can finish the second amp next week so I can use them bridged @15w.
Cheers
Well that's the key.
Is that 1.4V peak or RMS?
Vp x 0.707 = Vrms
Vp = Vrms x 1.414
ACA needs I think (and I might be slightly off) around 4Vp in to produce full power.
I drive mine with B1 buffer and speakers are 93 - 94dB, plenty loud.
My DAC's specs are listed as follows:
Output level low
0.282 VRMS Balanced
0.141 VRMS Single Ended
Output level high maximum
2.818 VRMS Balanced
1.414 VRMS Single Ended
What is a B1 buffer? Maybe I am going deaf
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Ha ha, don't think you are going deaf.
B1 buffer is one of Mr. Pass creations, a sort of preamp with no gain.
You'll find a lot of references here at DIYAudio.
As I said:
Vp = 1.414 x 1.414 = 1.99Vrms
that is low
Your ACA is running at roughly half power and considering that it is a 4W device that is not much at all.
You'll need an active pre like B1Korg or ACP+ or any pre with Av = 3 - 6 (10 - 15dB).
If you are into tubes a 12B4A stage will fit nicely and also restore the polarity of the signal.
B1 buffer is one of Mr. Pass creations, a sort of preamp with no gain.
You'll find a lot of references here at DIYAudio.
As I said:
Vp = 1.414 x 1.414 = 1.99Vrms
that is low
Your ACA is running at roughly half power and considering that it is a 4W device that is not much at all.
You'll need an active pre like B1Korg or ACP+ or any pre with Av = 3 - 6 (10 - 15dB).
If you are into tubes a 12B4A stage will fit nicely and also restore the polarity of the signal.
Alright, so I am learning a lot just trying to understand your response. hahaha. I had to look up what "Vp" and "AV" was. I ordered a pre-amp about a month ago, but it's still getting made. It's about 2 weeks behind schedule so far. This preamp is rated at ~2 Vrms for the RCA output level, so if I'm understanding you correctly, that should bring up the volume. My Vp should be about 4Vrms.
I was wondering why everything I read said that my ACA and my F8 should be plenty loud with my 96 dB Klipsch speakers. I'm not going crazy or deaf. Best news of 2021. Thank you!
Since I don't know if this preamp will ever ship, maybe there is a preamp DIY kit I can put together. Is the B1Korg short for the Korg Nutube B1 that I see at the DIYAudio store? If it is, maybe it can be my 2nd DIY build. I recently built the ACA, hopefully the difficulty is on par or not too far off from that.
Help! I have been running my pair of ACAs in parallel mode for for a few months now. I had a problem several weeks ago where the amp feeding the left speaker dropped out. LEDs were still on but no sound. When I moved the amp the sound returned and I traced the problem back to a loose DC socket, I bent the pin on this to make a tighter fit and all seemed ok for a while.
Yesterday I thought the left speaker was dropping in and out and checked the amp, one of the heatsinks was stone cold!! I have removed the amp and checked the offset on the cold side, it has dropped to 7.5v, not sure if this is significant but I'm not sure how best to proceed with fault finding?
Yesterday I thought the left speaker was dropping in and out and checked the amp, one of the heatsinks was stone cold!! I have removed the amp and checked the offset on the cold side, it has dropped to 7.5v, not sure if this is significant but I'm not sure how best to proceed with fault finding?
Start with the basic voltage and resistance checks in the build guide Step 56 (Amp Camp Amp V1.6 Build Guide - diyAudio Guides)
Compare your results to the the good side.
Likely a poor solder joint that has failed due to thermal cycling.
Compare your results to the the good side.
Likely a poor solder joint that has failed due to thermal cycling.
@ captain_pugwash. Sounds like the connector again. Remember that it takes no current at all to run an LED. But it takes a good deal of current to run the amplifier. Equate it to a car with a loose battery post. You open the door and the dome light comes on. You try to start the engine and you it clunks once but won’t turn over. You might have to replace that connector. It sounds like it cannot sink the current of the amp. I had one that gave me fits, )totally my fault for overheating it) on the initial build.
On another builder induced error I had the same behavior from the power switch. Again, the LED would light but the switch couldn’t sink the current. For that, I joined the two switch leads together with a wire nut because my stuff is on a power strip anyway.
You can test that by shorting the switch leads together with an alligator clip, or even a screwdriver.
On another builder induced error I had the same behavior from the power switch. Again, the LED would light but the switch couldn’t sink the current. For that, I joined the two switch leads together with a wire nut because my stuff is on a power strip anyway.
You can test that by shorting the switch leads together with an alligator clip, or even a screwdriver.
Hello!
New day, new listening session
My preamp (a Project StreamBox RS with tube) can deliver 1V only, so I can listen at normal volumes, but not really loud with my Sonus Faber Venere 2.5. Normally I use a Copland CSA-28 integrated amp (or a Rega Elicit-R, but I don't like it anymore).
My first impression is, that the mids are gorgeous. Allan Taylor or Josh Kelley are just standing in front of me, great. The voice of Amy Duncan comes with all the facets very live-like. The bass is deep and "black" if that makes sense
So... as the President said in "Independence Day", "not bad, not bad at all..."
Hopefully I can finish the second amp next week so I can use them bridged @15w.
Cheers
Nice report - Project make some nice gear, I have speedbox for my turntable. Second ACA running bridged or balanced will take a touch of sweetness out but the project should keep it sweet enough. Much easier to try parallel in the 1.8 version which someone on here told me they prefer.
I’m using Nutube pre-amp in 2U case with Elma rotary switch for four inputs and TKD volume pot. I love it. But I have Naim Atom headphone amp due for delivery any day now upgrading my DAC and replacing a broken streamer in one convenient package. It has XLR outputs as well as RCA so I’ll be trying the ACA in balanced mode for the first time. I’ve read one review of the Naim running a First watt F8 So I’m crossing everything that it’s a good match for the ACA. I’ll keep the Nutube and build a third ACA for desktop use when I’m less broke.
So, more or less yes, still... your units indicate that there is still a missing concept. When you say "My Vp should be about 4Vrms"... there is something wrong there: Volts peak-to-peak, or Vpp is one way to measure the amplitude, Vrms or root mean square is yet another way to measure amplitude.
So, your Vpp should be 4V (this is already clipping on my ACA, but I have a v1.0 with 19V PSU). Or, if you are measuring in Vrms, it should be a PRE capable of 2.8Vrms.
Very quick read in Wikipedia if my examples are not clear enough:
Amplitude - Wikipedia
Missed the part about one heatsink.
No it probably wouldn’t so check out the v+ connection between the switch and the card with no warmth.
Hi Steve,
thank you!
Yes, the Projects are really good, but I plan to build the B1K instead. With only 1V output the Project don't really fit with the ACA. And a sensitive speaker is a must, and of course it should also be a diy, hope I will get some help here. My FH MkIII is very special concerning the placement so I need a more universal speaker.
Good to read that you are satisfied with the Nutube-ACA-combination!
thank you!
Yes, the Projects are really good, but I plan to build the B1K instead. With only 1V output the Project don't really fit with the ACA. And a sensitive speaker is a must, and of course it should also be a diy, hope I will get some help here
. My FH MkIII is very special concerning the placement so I need a more universal speaker. Good to read that you are satisfied with the Nutube-ACA-combination!