Anyone reckon the Pass amp would work well with a pair of 705’s? Or perhaps as monoblocks, which apparently is a build option? Thanks.
Ehhh.... I'd pass...... the 705's need a decent amount of wattage and current, and the pass aren't built to do either of those to the scale you'd need.
"....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
Performance-wise, the original morph of the ACA isn't all that dissimilar to a single-ended 2A3 amplifier -- albeit a bit more powerful and probably wider flat response compared to any even marginally affordable 2A3 stereo amp.
So... think SET/fleapower friendly loudspeakers.
Vintage Altec, JBL or (shudder) Klipsch fills the bill nicely (e.g.).
So 'Doc' I can't believe no one has asked you about this after all these years. Why didn't you paint or ,stain those speakers. They stand out like very sor thumbs and need some beautification. Being an old Yankee you must have some Marine varnish up there so throw some coats on. and counter sink those screws. Chemistry and radionics are your strong suit but not to much on the the aesthetic. Look who's the critic now ....lol
Also with as much as he's tweaked them over the years at times (adding in super tweeters, other horns, etc) at the top of them it wouldnt make sense IMHO to finish them.
"....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
The kits came in yesterday, spent Sunday building. The monoblocks are now breaking in... er heating the room. Measured 126F at the heatsinks. The entire chassis is hot.
Living Room Music-2.0 Polk Legend L800 | McIntosh C70 | McIntosh MA5200 (Treble) | McIntosh MC452 (Bass) | Sublimeacoustic K231 Active xover | Denon DP-2500A | Marantz HD-CD1 | Denafrips Aries II | Amazon Music Ultra HD via iPad Pro Family Room Home Theater-7.2.2 (Atmos) Polk LSiM 707, 706c, Dual DSW microPRO 3000, LSiM 702 F/X [x4], RC65i | Marantz SR7009 | Marantz PM-10 [FL/FR] | Marantz SA-10 | Sony UBP-X800 4K | Xbox One S 4K | AppleTV 4K | HTPC | Sony 75” XBR X850D 4K Office Home Theater-5.1 Polk RT55, CS400, PSW450, f/x 500 | Onkyo TX-SR705 | AppleTV | Samsung 55” Office Music-2.0 KEF Q100 | Sansui AU-6900 | Topping DX7s | Sansui FR-1080 Office Music 2-2.0 Klipsch RP-600M | Topping DX7s (BAL out) | PASS ACA (kit) Class A balanced monoblocks Master Bedroom Music-2.0 Totem Hawk | Rotel RA-1570 Patio Music-2.0 Polk Atrium8 | AMC 2445 bridged Airplay zones: Family Room (HDMI), Family Room SA-10 (optical), Master Bedroom (Optical), Office (HDMI), Office DX7s (optical), Living Room Ares (Optical), SR7009 (AVR direct) and Patio (analog). Apple Music multi-stream to any, combo or all. Spares: Polk LSi25, LSiC, CS300, 4pr T15, Martin Logan Motion 40, 50xt, Dynamo 500, Rotel RB-1590, Denon AVR-4802R, Onkyo DX-C540, DVP-S500D, PS HX-500, Maintenance: Pro-Ject VC-S Record Cleaning Machine
So I've played them for a little bit but two things.
1) Polk T15 are not the best speakers. I also have a pair of ML Motion 40's sitting around but these are 4ohms and the bridged mono's look to only be rated for 8 ohms or higher.
2) I need to redo the bias. I had followed the v1.5 build guide, these kits came with 19v supplies and bias is set at 10v. The new v1.6 kits come with 24v 5a supplies and should be biased at 12v per diyaudio.com members.
Living Room Music-2.0 Polk Legend L800 | McIntosh C70 | McIntosh MA5200 (Treble) | McIntosh MC452 (Bass) | Sublimeacoustic K231 Active xover | Denon DP-2500A | Marantz HD-CD1 | Denafrips Aries II | Amazon Music Ultra HD via iPad Pro Family Room Home Theater-7.2.2 (Atmos) Polk LSiM 707, 706c, Dual DSW microPRO 3000, LSiM 702 F/X [x4], RC65i | Marantz SR7009 | Marantz PM-10 [FL/FR] | Marantz SA-10 | Sony UBP-X800 4K | Xbox One S 4K | AppleTV 4K | HTPC | Sony 75” XBR X850D 4K Office Home Theater-5.1 Polk RT55, CS400, PSW450, f/x 500 | Onkyo TX-SR705 | AppleTV | Samsung 55” Office Music-2.0 KEF Q100 | Sansui AU-6900 | Topping DX7s | Sansui FR-1080 Office Music 2-2.0 Klipsch RP-600M | Topping DX7s (BAL out) | PASS ACA (kit) Class A balanced monoblocks Master Bedroom Music-2.0 Totem Hawk | Rotel RA-1570 Patio Music-2.0 Polk Atrium8 | AMC 2445 bridged Airplay zones: Family Room (HDMI), Family Room SA-10 (optical), Master Bedroom (Optical), Office (HDMI), Office DX7s (optical), Living Room Ares (Optical), SR7009 (AVR direct) and Patio (analog). Apple Music multi-stream to any, combo or all. Spares: Polk LSi25, LSiC, CS300, 4pr T15, Martin Logan Motion 40, 50xt, Dynamo 500, Rotel RB-1590, Denon AVR-4802R, Onkyo DX-C540, DVP-S500D, PS HX-500, Maintenance: Pro-Ject VC-S Record Cleaning Machine
I really wanted to pick one of these up, but I have 3 other projects and I have no current use for this little wonder amp.
"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass
Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S-Tubes add soul!
Have regrettably been away for quite a while but thought I'd check in re: the ACA.
This thing sounds FANTASTIC!
Meridian Exporer II Test
The day after it was finished I brought it in and hooked it up to a simple little computer rig to get some hours on it. The rig was:
PC (Roon Remote) > Jitterbug > Wireworld Starlight Red A/MiniB > Meridian Explorer II dac > AQ headphone-RCA adapter > MIT S3 interconnects > Amp Camp Amp > MIT S3 speaker cables > Hartley Reference Mini-Towers
I believe the speakers are 95db but am not certain. The room is about 12'x12' with an 8ft opening centered on the back wall. Using Roon's software volume control, I needed to set it 80ish% for most music; but, at 90% it provided plenty of gain for any music I played.
Amazing clarity and detail, excellent soundstage with instruments spread evenly from ~5 degrees outside the speakers. Fantastic, detailed bass. Not sure how to describe this, but it has an addictive purity of tone; detailed but not brittle; lush but not overly sweet - it just sounded right and true. The best sound I've ever had in this location. Instantly fell in love with it. I was ecstatic, especially given this is not, what I assume to be, an optimal rig.
Audio Research LS-3
I ordered a Schiit Saga to try out. While waiting for it to arrive, I tried the ACA with my usual sources in the study and an AR solid state pre:
Way more gain - too much in both passive and active - and the sound suffered and was no longer magical. Reverted to the Meridian-direct source while waiting a little longer for the Saga.
Schiit Saga
Saga arrived a few days ago, so I slotted into the Bryston source rig. Sounds noticeably better than the Meridian-direct (or is it the Bryston's?, likely a combo of both). But, a bit surprising to me, the Saga does not add any gain - in fact, it seems to be less. In passive, I have to turn it to 3:00 to listen to most things at a realistic volume. Still fantastically detailed, but I do worry about distortion at that level (or higher when I'm feeling my oats). Switching to the tube adds the slightest amount of gain (I think) but is barely perceptible. I like the little Schiit enough to keep and try with other gear. I'll also try to slot in the Joule pre for fun, even though they won't likely be paired for any length of time.
I have yet to build Frugel-horn cabinets or similar (hope to do that this month), and am considering used Zu Omens or new Tekton Double Impacts. But for now, I'm happy as a clam listening to this lovely little amp with stuff that I have on hand.
I HIGHLY recommend this amp if you get the opportunity to buy a kit or an assembled one. Many thanks to @mhardy6647 for the heads-up on availability.
Dang it! After your review, I think I want one again
SOLD out again..............I'm on the waiting list, AGAIN...lol
H9
"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass
Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S-Tubes add soul!
The only "problem" with the ACA relative to SE DHT(2A3) amplifier (in my hands, that is) is that it doesn't quite have the midrange realness of the 2A3 amp. It is just a bit drier sounding (but there's probably a certain amount of expectation bias goin' on, too!). You all probably recall the one that is on a long-term visit (maybe it's a hostage?!) here; it's a little tricked up relative to the stock (first generation, I think) ACA configuration.
Otherwise, it is at least in the running with a decent quality SE 2A3 amplifier. Bass may be a little better (not necessarily easy to tell with my loudspeakers). Certainly cheaper than SE 2A3 and its hottest parts don't run as hot as a pair of 2A3 output tubes in Class A I suspect (but haven't checked) that power consumption of the ACA (the one here, it may be recalled, is physically configured as a stereo amp with a "Bottlehead" like footprint) and the 2A3 amp are comparable.
Another question for the DOC here. You went fairly in depth in soldering and how to get the right heat and flow. What you did not specify is the type of instrument you personally use. Is it a tried and true Weller, the portable butane type, old school pencil type w/ holder, and a very old and large enough to weld a Liberty ship called the Cummings.
Lew.....
I am seriously not an expert on modering soldering stations.
I (still) like the Weller controlled heat stations... but there may well be better; I dunno.
Comments
Ehhh.... I'd pass...... the 705's need a decent amount of wattage and current, and the pass aren't built to do either of those to the scale you'd need.
"Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
So... think SET/fleapower friendly loudspeakers.
Vintage Altec, JBL or (shudder) Klipsch fills the bill nicely (e.g.).
Amp Camp Amp - Complete Kit (PRE-ORDER, SHIPS SEP 15TH) – diyAudio Store
Post fromJason @diyaudio.com
Family Room Home Theater-7.2.2 (Atmos) Polk LSiM 707, 706c, Dual DSW microPRO 3000, LSiM 702 F/X [x4], RC65i | Marantz SR7009 | Marantz PM-10 [FL/FR] | Marantz SA-10 | Sony UBP-X800 4K | Xbox One S 4K | AppleTV 4K | HTPC | Sony 75” XBR X850D 4K
Office Home Theater-5.1 Polk RT55, CS400, PSW450, f/x 500 | Onkyo TX-SR705 | AppleTV | Samsung 55”
Office Music-2.0 KEF Q100 | Sansui AU-6900 | Topping DX7s | Sansui FR-1080
Office Music 2-2.0 Klipsch RP-600M | Topping DX7s (BAL out) | PASS ACA (kit) Class A balanced monoblocks
Master Bedroom Music-2.0 Totem Hawk | Rotel RA-1570
Patio Music-2.0 Polk Atrium8 | AMC 2445 bridged
Airplay zones: Family Room (HDMI), Family Room SA-10 (optical), Master Bedroom (Optical), Office (HDMI), Office DX7s (optical), Living Room Ares (Optical), SR7009 (AVR direct) and Patio (analog). Apple Music multi-stream to any, combo or all.
Spares: Polk LSi25, LSiC, CS300, 4pr T15, Martin Logan Motion 40, 50xt, Dynamo 500, Rotel RB-1590, Denon AVR-4802R, Onkyo DX-C540, DVP-S500D, PS HX-500,
Maintenance: Pro-Ject VC-S Record Cleaning Machine
H/T- Toshiba au40" flat- Yamaha RX- V665 avr- YSD-11 Dock- I-Pod- Klipsch #400HD Speaker set-
Bdrm- Nikko 6065 receiver- JBL -G-200s--Pioneer 305 headphones--Sony CE375-5 disc
Also with as much as he's tweaked them over the years at times (adding in super tweeters, other horns, etc) at the top of them it wouldnt make sense IMHO to finish them.
Family Room Home Theater-7.2.2 (Atmos) Polk LSiM 707, 706c, Dual DSW microPRO 3000, LSiM 702 F/X [x4], RC65i | Marantz SR7009 | Marantz PM-10 [FL/FR] | Marantz SA-10 | Sony UBP-X800 4K | Xbox One S 4K | AppleTV 4K | HTPC | Sony 75” XBR X850D 4K
Office Home Theater-5.1 Polk RT55, CS400, PSW450, f/x 500 | Onkyo TX-SR705 | AppleTV | Samsung 55”
Office Music-2.0 KEF Q100 | Sansui AU-6900 | Topping DX7s | Sansui FR-1080
Office Music 2-2.0 Klipsch RP-600M | Topping DX7s (BAL out) | PASS ACA (kit) Class A balanced monoblocks
Master Bedroom Music-2.0 Totem Hawk | Rotel RA-1570
Patio Music-2.0 Polk Atrium8 | AMC 2445 bridged
Airplay zones: Family Room (HDMI), Family Room SA-10 (optical), Master Bedroom (Optical), Office (HDMI), Office DX7s (optical), Living Room Ares (Optical), SR7009 (AVR direct) and Patio (analog). Apple Music multi-stream to any, combo or all.
Spares: Polk LSi25, LSiC, CS300, 4pr T15, Martin Logan Motion 40, 50xt, Dynamo 500, Rotel RB-1590, Denon AVR-4802R, Onkyo DX-C540, DVP-S500D, PS HX-500,
Maintenance: Pro-Ject VC-S Record Cleaning Machine
Can't wait to hear the listening impressions.
What will be the rest of the setup?
126 ain't bad (assuming that's Fahrenheit kind of degrees, and not those Commie Celsius degrees
1) Polk T15 are not the best speakers. I also have a pair of ML Motion 40's sitting around but these are 4ohms and the bridged mono's look to only be rated for 8 ohms or higher.
2) I need to redo the bias. I had followed the v1.5 build guide, these kits came with 19v supplies and bias is set at 10v. The new v1.6 kits come with 24v 5a supplies and should be biased at 12v per diyaudio.com members.
Family Room Home Theater-7.2.2 (Atmos) Polk LSiM 707, 706c, Dual DSW microPRO 3000, LSiM 702 F/X [x4], RC65i | Marantz SR7009 | Marantz PM-10 [FL/FR] | Marantz SA-10 | Sony UBP-X800 4K | Xbox One S 4K | AppleTV 4K | HTPC | Sony 75” XBR X850D 4K
Office Home Theater-5.1 Polk RT55, CS400, PSW450, f/x 500 | Onkyo TX-SR705 | AppleTV | Samsung 55”
Office Music-2.0 KEF Q100 | Sansui AU-6900 | Topping DX7s | Sansui FR-1080
Office Music 2-2.0 Klipsch RP-600M | Topping DX7s (BAL out) | PASS ACA (kit) Class A balanced monoblocks
Master Bedroom Music-2.0 Totem Hawk | Rotel RA-1570
Patio Music-2.0 Polk Atrium8 | AMC 2445 bridged
Airplay zones: Family Room (HDMI), Family Room SA-10 (optical), Master Bedroom (Optical), Office (HDMI), Office DX7s (optical), Living Room Ares (Optical), SR7009 (AVR direct) and Patio (analog). Apple Music multi-stream to any, combo or all.
Spares: Polk LSi25, LSiC, CS300, 4pr T15, Martin Logan Motion 40, 50xt, Dynamo 500, Rotel RB-1590, Denon AVR-4802R, Onkyo DX-C540, DVP-S500D, PS HX-500,
Maintenance: Pro-Ject VC-S Record Cleaning Machine
Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
This thing sounds FANTASTIC!
Meridian Exporer II Test
The day after it was finished I brought it in and hooked it up to a simple little computer rig to get some hours on it. The rig was:
PC (Roon Remote) > Jitterbug > Wireworld Starlight Red A/MiniB > Meridian Explorer II dac > AQ headphone-RCA adapter > MIT S3 interconnects > Amp Camp Amp > MIT S3 speaker cables > Hartley Reference Mini-Towers
I believe the speakers are 95db but am not certain. The room is about 12'x12' with an 8ft opening centered on the back wall. Using Roon's software volume control, I needed to set it 80ish% for most music; but, at 90% it provided plenty of gain for any music I played.
Amazing clarity and detail, excellent soundstage with instruments spread evenly from ~5 degrees outside the speakers. Fantastic, detailed bass. Not sure how to describe this, but it has an addictive purity of tone; detailed but not brittle; lush but not overly sweet - it just sounded right and true. The best sound I've ever had in this location. Instantly fell in love with it. I was ecstatic, especially given this is not, what I assume to be, an optimal rig.
Audio Research LS-3
I ordered a Schiit Saga to try out. While waiting for it to arrive, I tried the ACA with my usual sources in the study and an AR solid state pre:
Roon > ethernet > Bryston BDP-1 > Bryston BNC > Bryston BDA-1 > MIT S3 > ARC LS-3 > MIT S3 > Amp Camp Amp > Hartley Ref MiniTower
Way more gain - too much in both passive and active - and the sound suffered and was no longer magical. Reverted to the Meridian-direct source while waiting a little longer for the Saga.
Schiit Saga
Saga arrived a few days ago, so I slotted into the Bryston source rig. Sounds noticeably better than the Meridian-direct (or is it the Bryston's?, likely a combo of both). But, a bit surprising to me, the Saga does not add any gain - in fact, it seems to be less. In passive, I have to turn it to 3:00 to listen to most things at a realistic volume. Still fantastically detailed, but I do worry about distortion at that level (or higher when I'm feeling my oats). Switching to the tube adds the slightest amount of gain (I think) but is barely perceptible. I like the little Schiit enough to keep and try with other gear. I'll also try to slot in the Joule pre for fun, even though they won't likely be paired for any length of time.
I have yet to build Frugel-horn cabinets or similar (hope to do that this month), and am considering used Zu Omens or new Tekton Double Impacts. But for now, I'm happy as a clam listening to this lovely little amp with stuff that I have on hand.
I HIGHLY recommend this amp if you get the opportunity to buy a kit or an assembled one. Many thanks to @mhardy6647 for the heads-up on availability.
Craig
Study: Roon * ProJect Stream Box Ultra & Pre Box S2 * Pass ACA * PSA Dectet * DH Labs Q10 * Brines Folded ML-TQWT RS 40-1354
Studio: Roon * LG v30 phone * Dared MP-5 * DefTech SM45
Beach: Rega RP6 * AT33PTGII * Budgie SUT * Jolida jd9 * Roon * Sonore UltraRendu (LPS-1, WW Plat7, Iso Regen, Lush) * Schiit Yggdrasil * Joule-Electra LA-100 mkIII * Pass Aleph 30 / First Watt F5 Clone * PSA Dectet * MIT S3 * Polk SRS 2.3tl
Beach Den: Sonore microRendu * Dayens Menuetto * Fostex BK-12m Folded Horn / KEF LS50 / Dynaudio Audience 50 / Revel M22
SOLD out again..............I'm on the waiting list, AGAIN...lol
H9
Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
Otherwise, it is at least in the running with a decent quality SE 2A3 amplifier. Bass may be a little better (not necessarily easy to tell with my loudspeakers). Certainly cheaper than SE 2A3
Family Room Home Theater-7.2.2 (Atmos) Polk LSiM 707, 706c, Dual DSW microPRO 3000, LSiM 702 F/X [x4], RC65i | Marantz SR7009 | Marantz PM-10 [FL/FR] | Marantz SA-10 | Sony UBP-X800 4K | Xbox One S 4K | AppleTV 4K | HTPC | Sony 75” XBR X850D 4K
Office Home Theater-5.1 Polk RT55, CS400, PSW450, f/x 500 | Onkyo TX-SR705 | AppleTV | Samsung 55”
Office Music-2.0 KEF Q100 | Sansui AU-6900 | Topping DX7s | Sansui FR-1080
Office Music 2-2.0 Klipsch RP-600M | Topping DX7s (BAL out) | PASS ACA (kit) Class A balanced monoblocks
Master Bedroom Music-2.0 Totem Hawk | Rotel RA-1570
Patio Music-2.0 Polk Atrium8 | AMC 2445 bridged
Airplay zones: Family Room (HDMI), Family Room SA-10 (optical), Master Bedroom (Optical), Office (HDMI), Office DX7s (optical), Living Room Ares (Optical), SR7009 (AVR direct) and Patio (analog). Apple Music multi-stream to any, combo or all.
Spares: Polk LSi25, LSiC, CS300, 4pr T15, Martin Logan Motion 40, 50xt, Dynamo 500, Rotel RB-1590, Denon AVR-4802R, Onkyo DX-C540, DVP-S500D, PS HX-500,
Maintenance: Pro-Ject VC-S Record Cleaning Machine
Another question for the DOC here. You went fairly in depth in soldering and how to get the right heat and flow. What you did not specify is the type of instrument you personally use. Is it a tried and true Weller, the portable butane type, old school pencil type w/ holder, and a very old and large enough to weld a Liberty ship called the Cummings.
Lew.....
]
H/T- Toshiba au40" flat- Yamaha RX- V665 avr- YSD-11 Dock- I-Pod- Klipsch #400HD Speaker set-
Bdrm- Nikko 6065 receiver- JBL -G-200s--Pioneer 305 headphones--Sony CE375-5 disc
I (still) like the Weller controlled heat stations... but there may well be better; I dunno.
Study: Roon * ProJect Stream Box Ultra & Pre Box S2 * Pass ACA * PSA Dectet * DH Labs Q10 * Brines Folded ML-TQWT RS 40-1354
Studio: Roon * LG v30 phone * Dared MP-5 * DefTech SM45
Beach: Rega RP6 * AT33PTGII * Budgie SUT * Jolida jd9 * Roon * Sonore UltraRendu (LPS-1, WW Plat7, Iso Regen, Lush) * Schiit Yggdrasil * Joule-Electra LA-100 mkIII * Pass Aleph 30 / First Watt F5 Clone * PSA Dectet * MIT S3 * Polk SRS 2.3tl
Beach Den: Sonore microRendu * Dayens Menuetto * Fostex BK-12m Folded Horn / KEF LS50 / Dynaudio Audience 50 / Revel M22