Parasound HCA 1201A monoblocks

[Orbit]

Hello,

 

There is a set of these for sale close enough to grab.  $150 for the set.  They would be way more amp than needed for my La Scalas.  Any inference into the possibility of them sounding good or being worth it for parts to build monoblocks for 2 channel is much appreciated.  

 

MFG's website is one of the few sources of info on these.

 

Your Parasound HCA-1201A High Current Mono-Block Power Amplifier was built using only the finest precision components available for optimum musical quality and performance. The HCA-1201A High Current Power Amplifier has a 280 VA toroidal power transformer and 20,000 uF of filter capacitance to provide the high levels of power needed for some of today�s more sophisticated speaker systems. The inherently low output impedance of the HCA-1201A easily maintains control of your loudspeakers even during demanding impedance variations.Unique circuit topology of the direct coupled HCA-1201A includes balanced JFET input transistors, bipolar drivers and ultra high current output devices. Additionally, there are no inductors or capacitors in the signal path. These design refinements reduce high odd-order harmonic distortion, improve overall clarity and preserve low-level musical details

FEATURES

• THX Ultra certified by Lucasfilm Ltd.
• 280 VA power transformer, 20,000 uF filter capacitance
• Massive toroid power transformer
• Multiple polystyrene film bypass capacitors in power supply
• Can be powered with external DC source
• Cascode Class A input stages with matched J-FET pairs
• Complementary transistors in high voltage driver stage
• 12 ampere 50 MHz output transistors
• Output transistors direct-coupled to speakers without LRC networks
• Direct-coupled audio circuits with 0.8 Hz rolloff
• High-bias Class A/AB operation
• Gold-plated RCA input jacks
• Multiple protection circuits
• Glass epoxy circuit boards, double-sided for precision
• Audiophile-grade AC power cord

SPECIFICATIONS

• Continuous Power Output:
      150 watts RMS, 20 Hz-20 kHz
      8 Ω 240 watts RMS, 20 Hz-20 kHz, 4 Ω
• Current Capacity:
      36 Amps peak
• Slew Rate:
      > 130 V/microsecond
• Power Bandwidth:
      5 Hz-100 kHz, +0/-3 dB at 1 watt
• Total Harmonic Distortion:
      < 0.03 % at full power
      < 0.01 % typical levels
• IM Distortion:
      < 0.03 %
• TIM:
      Unmeasureable
• Dynamic Headroom:
      > 1.5 dB
• Input Impedance:
      33 k Ω
• Input Sensitivity:
      1 V for 28.28 V;
      THX Reference Level; 1.2 V for full output
• S/N Ratio:
      > 120 dB full power
      > 96 dB THX reference level
• Damping Factor:
      > 800 at 20 Hz
• Dimensions:
      6 1/4" wide x 5 1/2" high x 16" deep
• Power Requirements:
      110 Vac-120 Vac 360 Watts
• Net Weight:

[billybob]

Yes, would scoop them up if decent working condition.

[Orbit]

13 minutes ago, billybob said:

Yes, would scoop them up if decent working condition.

Thank you for the quick reply.  I reached out to the seller.

[billybob]

1 minute ago, Orbit said:

Thank you for the quick reply.  I reached out to the seller.

Time likely of the essence. 

[Orbit]

36 minutes ago, billybob said:

Time likely of the essence. 

Well thanks to some quick acting I am going to get them and a Marchand XM9 crossover for another $75.  Thanks Billybob

[billybob]

2 minutes ago, Orbit said:

Well thanks to some quick acting I am going to get them and a Marchand XM9 crossover for another $75.  Thanks Billybob

Hope it all works out. Let know.

[OO1]

2 hours ago, Orbit said:

Hello,

 

There is a set of these for sale close enough to grab.  $150 for the set.

no brainer ,  the seller has no idea what these are worth , but make sure they have no issues cause if they need repairs

[jjptkd]

53 minutes ago, Orbit said:

Well thanks to some quick acting I am going to get them 

These are some of the lowest rated amps I've seen on Audioreview build quality seems bad specs when compared to the HCA-1000a aren't that impressive to say the least also no mention of John Curl-- his name is typically plastered all over his work:

 

http://www.audioreview.com/product/amplification/amplifiers/parasound/hca-1201a.html

 

https://www.parasound.com/vintage/hca1000a.php

[billybob]

Yes mixed reviews on the site audioreview I went to earlier. At the price, think OP will be happy...cool.

[captainbeefheart]

Just make sure they are in good working order and not just powers up because if they need to be repaired be prepared to pay a lot more than $150. Not to say there are not great deals out there but with the internet it has become a lot harder to grab something very cheap because the seller doesn't know what they have, all someone now has to do is google it and they can see what they are selling for and what they sold for new within minutes. Often if it's too good to be true be wary.

[billybob]

Yes, wary...

[Orbit]

1 hour ago, jjptkd said:

These are some of the lowest rated amps I've seen on Audioreview build quality seems bad specs when compared to the HCA-1000a aren't that impressive to say the least also no mention of John Curl-- his name is typically plastered all over his work:

 

http://www.audioreview.com/product/amplification/amplifiers/parasound/hca-1201a.html

 

https://www.parasound.com/vintage/hca1000a.php

I appreciate this.  Looks like most of these are related to dead units and poor soldering.  I will be sure to open one up.  Thank you

[captainbeefheart]

Another point of view is that people forget that these amps originally were not expensive brand new, they are budget amps. There are lots of bad reviews on the internet about them being cheaply made so then again the seller might be having a hard time selling them and just listed them with a has to go price and there is nothing wrong with them.

 

The people that gave the poor reviews on the product fail to remember the fact that these amps were very inexpensive compared to other products produced by them so of course there is going to be some degree of cost cutting in the design. As long as they function properly and you don't abuse them you will have done good getting the two for only $150.

[billybob]

Indeed, we shall see...

[Orbit]

 

 

 

 

3 hours ago, captainbeefheart said:

Another point of view is that people forget that these amps originally were not expensive brand new, they are budget amps. There are lots of bad reviews on the internet about them being cheaply made so then again the seller might be having a hard time selling them and just listed them with a has to go price and there is nothing wrong with them.

 

The people that gave the poor reviews on the product fail to remember the fact that these amps were very inexpensive compared to other products produced by them so of course there is going to be some degree of cost cutting in the design. As long as they function properly and you don't abuse them you will have done good getting the two for only $150.

They will be running the La Scala for now so i won't be putting much strain on them.  I can't comfortably put Sansui g-3500 past 3.  Now I just need to find a preamp.  Hopefully with balanced outs.

[billybob]

2 hours ago, Orbit said:

 

 

 

 

They will be running the La Scala for now so i won't be putting much strain on them.  I can't comfortably put Sansui g-3500 past 3.  Now I just need to find a preamp.  Hopefully with balanced outs.

Meanwhile, do you have preouts on the Sansui? 

Don't know if good match but a Parasound preamp in garage sale here. Guess you will be getting the amps soon so may be premature.

[Orbit]

On 2/17/2022 at 8:35 PM, billybob said:

Meanwhile, do you have preouts on the Sansui? 

Don't know if good match but a Parasound preamp in garage sale here. Guess you will be getting the amps soon so may be premature.

The Sansui is sans a preamp out.  I can go out of my DAC/streamer into the amps and sub.  This is causing a 120hz hum in both the la scala and the sub.  

 

Aside from the hum the signal is noticeably more dynamic and clear with these amps.  

 Any tips to get rid of the 120hz hum?  I isolated the issue to the Streamer/DAC.  

All 3 amps have the hum as soon as the Streamer/DAC gets power.

[Orbit]

Put one of the amps on another circuit and the 120hz hum is gone.  Amps are dead quiet in the La Scala. Imaging is a large improvement over the Sansui.  

Right now there is only one gain knob in the system for the La Scala.  The Echo Link is going straight into the Parasounds.  

I would not describe the sound as warm.  Most noticeable are the vocal inflections on Steely Dan tracks.  They are more pronounced.

I am left wondering what a preamp could do to enhance the sound. 

[captainbeefheart]

32 minutes ago, Orbit said:

Put one of the amps on another circuit and the 120hz hum is gone.  Amps are dead quiet in the La Scala. Imaging is a large improvement over the Sansui.  

Right now there is only one gain knob in the system for the La Scala.  The Echo Link is going straight into the Parasounds.  

I would not describe the sound as warm.  Most noticeable are the vocal inflections on Steely Dan tracks.  They are more pronounced.

I am left wondering what a preamp could do to enhance the sound. 

 

I have a Forte model II Class A preamp that I got in a trade, I was surprised at how good it sounded especially the phono section. I am currently happy with my all tube system and will most likely get rid of the Forte model II. If you decide on getting a preamp let me know and I'll sell it cheap, it would be a good match with the Parasound amps.

 

https://forum.audiogon.com/discussions/review-forte-model-2-preamplifier

[billybob]

 Cool...