nOrh Audio Control Amplifier Preamplifiers

5/5 (7 Reviews) MSRP : $900.00


Product Description

Dual Mono Preamp


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Reviews 1 - 5 (7 Reviews Total) | Next 15

User Reviews

Overall Rating:5
Value Rating:5
Submitted by tixxxa a Audio Enthusiast

Date Reviewed: February 24, 2002

Bottom Line:   
I'm not experienced at writing rewievs.

I listen mostly to classic and hard rock music. I had very high expectations to this preamp and monobocks I ordered. ACA-amp met about 96% of those expectations. I'm very pleased with the purchase.

Compared to onkyo I had, the improvement was evident (as it should have been).

Volume control goes in steps. Steps are steep but not too steep for my taste.

Delivery company took care of the taxes at the customs. I just had to transfer money to their account when the items arrived and the next thing was agreeing of the delivery time to my home. (For me there was +25% taxes to purchace price)

I got a lot of hum from the phono. It eased only when I connected the phono ground to rca ground at aca-amp end.

I'm sure there are pre-amps that are better than aca-amp in some or all areas. I'm also quite sure they are lot more expecive ones. This product is very well balanced (I mean like "Great highs but bass is little weak").

5 star over all rating was described as "far better than you imagined". For me the five star represent more like "Best you came around and got what you expected"

Expand full review >>

Used product for:   3 Months to 1 year

Duration Product Used:   Audio Enthusiast

Product model year:   2001

Price Paid:    $900.00

Purchased At:   manufacturer



Overall Rating:5
Value Rating:5
Submitted by Alex a Audiophile

Date Reviewed: August 6, 2001

Bottom Line:   
I have been searching for an affordable (around $2,000) preamp for months, to replace the old McIntosh tube. The McIntosh has reached its retirment age.

Tried a couple others. Including a passive. All works okay, but I still feel something is not right.

At the suggestion of another Odyssey Stratos owner (I also own two Odyssey Stratos.) I ordered the nOrh ACA preamp.

I received the nOrh ACA preamp in about a week after ordering.

The amp was packed very securly. It arrived without any damage.

The ACA is quite heavy in weight for its small size. It's a double decker. With the seperate power supplies at the bottom deck.

A nice feature is the AV bypass, where users can use the same poweramp and speakers with the music system, but in fact, have the rest of the HT seperated from the music system.

The ACA also have a very good RIAA/phono (MM) pre. And a "Copy" function. Great for transfering vinyls to CD-Rs.

The ACA have silver aluminium faceplate and matt black chasis. Just a volume and selector knobs, a copy and headphone switches, and indicator lights on the top deck, and a single black on/off switch and indicator light at the bottom deck.

The whole thing is very solid. And the silver front aluminium faceplate looks very nice sitting by the silver Odyssey Stratos.

The ACA is bright before settling down. But after a couple of days. It smoothed out quite a bit, and keep getting better all the time.


My Odyssey Stratos are well broken-in now (in use continuously for 19 months by now.). The imaging and soundstaging are already hard to beat. But when I connected the ACA to the Stratos. Man... I was in for a big surprise. The ACA just let more information from the recording through. More details, more ambients, more subtle and not so subtle dynamics. The soundstage and imaging just opened up even more.

All the other preamps I have used were restricting the full protential of the Stratos. Even before the addition of the ACA. The performance level was already better than many other more costly systems. But the ACA just lift the level up by several notches.

The improvment is like moving from a regularPorsche Carerra up to a Porche Carerra 4!

The ACA have just unleashed the full protential of the Odyssey Stratos.

The system is still improving. I keep hearing new details coming out from old recordings.

I'm so impressed with the ACA, I got the CD-1 from nOrh as well, plus the 6.9 SM drum speakers.

Well. Those are for another review.

nOrh has anounced a new nOrh ACA preamp. The ACA-2 will not have the phono input. But more regular input. And said to be even a better performer than the current one. nd at a lower price as well.

I have noreason to doubt it. Based on my very positive impression with all my dealings with nOrh electronics and speakers.

You cannot go wrong.

Highly Recommanded.

Expand full review >>

Used product for:   3 months to 1 year

Duration Product Used:   Audiophile

Product model year:   2000

Purchased At:   http://norh.com/



Overall Rating:5
Value Rating:5
Submitted by Alex a Audiophile

Date Reviewed: August 6, 2001

Bottom Line:   
I have been searching for an affordable (around $2,000) preamp for months, to replace the old McIntosh tube. The McIntosh has reached its retirment age.

Tried a couple others. Including a passive. All works okay, but I still feel something is not right.

At the suggestion of another Odyssey Stratos owner (I also own two Odyssey Stratos.) I ordered the nOrh ACA preamp.

I received the nOrh ACA preamp in about a week after ordering.

The amp was packed very securly. It arrived without any damage.

The ACA is quite heavy in weight for its small size. It's a double decker. With the seperate power supplies at the bottom deck.

A nice feature is the AV bypass, where users can use the same poweramp and speakers with the music system, but in fact, have the rest of the HT seperated from the music system.

The ACA also have a very good RIAA/phono (MM) pre. And a "Copy" function. Great for transfering vinyls to CD-Rs.

The ACA have silver aluminium faceplate and matt black chasis. Just a volume and selector knobs, a copy and headphone switches, and indicator lights on the top deck, and a single black on/off switch and indicator light at the bottom deck.

The whole thing is very solid. And the silver front aluminium faceplate looks very nice sitting by the silver Odyssey Stratos.

The ACA is bright before settling down. But after a couple of days. It smoothed out quite a bit, and keep getting better all the time.


My Odyssey Stratos are well broken-in now (in use continuously for 19 months by now.). The imaging and soundstaging are already hard to beat. But when I connected the ACA to the Stratos. Man... I was in for a big surprise. The ACA just let more information from the recording through. More details, more ambients, more subtle and not so subtle dynamics. The soundstage and imaging just opened up even more.

All the other preamps I have used were restricting the full protential of the Stratos. Even before the addition of the ACA. The performance level was already better than many other more costly systems. But the ACA just lift the level up by several notches.

The improvment is like moving from a regularPorsche Carerra up to a Porche Carerra 4!

The ACA have just unleashed the full protential of the Odyssey Stratos.

The system is still improving. I keep hearing new details coming out from old recordings.

I'm so impressed with the ACA, I got the CD-1 from nOrh as well, plus the 6.9 SM drum speakers.

Well. Those are for another review.

nOrh has anounced a new nOrh ACA preamp. The ACA-2 will not have the phono input. But more regular input. And said to be even a better performer than the current one. nd at a lower price as well.

I have noreason to doubt it. Based on my very positive impression with all my dealings with nOrh electronics and speakers.

You cannot go wrong.

Highly Recommanded.

Expand full review >>

Used product for:   3 months to 1 year

Duration Product Used:   Audiophile

Product model year:   2000

Purchased At:   http://norh.com/



Overall Rating:5
Value Rating:5
Submitted by Tien Pham a Audio Enthusiast

Date Reviewed: May 13, 2001

Bottom Line:   
When I first started into the high-end audio journey, I never knew that high-end equipment would cost so much. I must admit that I have a very hard time justifying paying over $ 3000.00 for a preamp. I can understand why amplifier could be expensive, because of the circuitry required to create the needed power to drive speakers. On the other hand, today’s preamps are not much more than a volume control with input selector.

I embarked on a journey to get the best preamp for my hard-earned money. After about four years and tried many preamps (Proceed Pre. BWS Tubes, Plinius 8200) I could not find any preamp cost under $ 4000.00 which satisfied me.

I finally got the ACA preamp two months ago. I was somewhat blown away when I first heard the sound of my system with the ACA. However, I decided to wait until now to write a review so that I could be fair. I did not want the first impression to take the better of me. Followings are my opinion of the ACA

a) Outside and Inside Constructions
I have a habit of opening up the equipment I buy to see where the money is spent and try to calculate the manufacturer/distributor/dealer’s markup.

The ACA is a very well built unit. The chassis is not as good as some of the very expensive preamp such as the Plinius M16, but very well build for $ 900.00.

Inside the unit is very clean and the wires are neatly tied. High quality parts are used through out. The volume control is the DACT series stepped attenuator (cost $ 160.00). Inputs/Outputs are switched via high-speed solid-state relays. The RCA jacks are high quality.

There is a total of three PCBs (Printed Circuit Board). I have been working in the electronic industry for the past 12 years, and I can tell that the PCBs are of high quality and would cost quite a bit.

The bottom case contains two 80W toroidal transformers. One for right channel and one for left channel. This is a true mono power supply (not a single transformer with dual secondary winding).

When I first looking at the part costs, I was puzzled on how nOrh managed to sell the unit for $ 900.00 including shipping. I estimated that it would cost me approximately $ 800.00 in parts a lone without the case, and I probably will have to spend many hours to put the unit together. I believe the key which allow nOrh to sell the unit so cheap is because of high volume order (lower part cost per unit), and low margin.

All in all, I am very happy to see that nOrh put most of the money into parts, which create sound.

b) Sound Stage
The ACA threw a huge sound stage. It beat the Proceed Pre and the Plinius 8200 in width, depth, and height.

The Proceed Pre sound stage is limited to the location of the speakers with depth about halfway between the speakers and the listening position, and the height just barely a foot above the listener ears. This is not important when I seat at the sweet spot but became critical as I stood up and walked around the room.

The Plinius 8200 sound stage is quite a bit better than the Proceed Pre preamp. Its sound stage extended about a foot beyond the speakers. The height is elevated at least three feet above the listener ears, and the depth is reached out all the way to the listener.

The ACA sound stage extended well beyond the speakers. In fact, with my eyes closed, it was fairly hard for me to tell where the speakers are placed. The height is well above the listener ears and stable vertically. The music does not change much as I stood up or sat down. The depth is all the way to the listening position. The combination of extended width, height, and depth put me in the middle of a concert hall.

The Plinius 8200 is very good but sound pale compare to the ACA, and the Proceed Pre is not even in the ballpark.

c) Imaging

The Proceed Pre imaging is fair and two dimensions. I can hear the single voice at the center of the stage with the instrument placed at the same distance.

The Plinius 8200 imaging is good and has a little bit of 3-D. The singer is in the middle of the stage with the band about a foot behind the singer.

The ACA is exceptional in 3-D imaging. I can clearly hear the singer voice with the band placed well behind the singer.

d) High frequency
This is an area where most solid state preamps fail measurably. All solid state preamps can play high frequency but most of them also have the harsh sound of solid state.

The Proceed pre had good frequency extension but dry with some harshness and not as real.

The 8200 did not have the harshness but somewhat rolled off or a bit fuzzy compare to the ACA.

The ACA has excellent frequency extension without any trace of harshness. Shimmer and Treble have the roundness and metal sound of the real musical instruments where as the Proceed Pre and the Plinius 8200 sound fuzzy and recorded.

e) Midrange
The ACA midrange is clear, precise, and more realistic than any active preamp I have heard. Both the Proceed Pre and the Plinius 8200 sound muffled compared to the ACA.

f) Bass
Once again the ACA is the clear winner. Its bass is much deeper and more control than the Proceed Pre and at least a notch better than the Plinius 8200.

This is very important to me because I am using the ACA with the Multiamp. The Multiamp exceeded the Plinius SA100 MK III (which I used to own) on midrange and treble. However, it cannot compete with the SA100 MK III in bass. I often wished that I had the midrange and treble of the Multiamp with the bass of the Plinius SA100 MK III. The ACA/Multiamp combo gave me my wish.

g) Transient/Dynamic
What I prefer to is the ability of the preamp to convey the speed of real the music instruments. I am talking about the transition between very slow music passages to extremely fast and dynamic ones.

The Proceed Pre and the Plinius 8200 sounded slow and congested. The timing between human voice and/or musical instruments were off.

The ACA managed to keep the timing correct with great dynamic. I could not detect any hint of congestion during the transition. It is as if the ACA is running at the same speed as the real music where as the Proceed Pre and the Plinius 8200 are running behind and trying to catch up.


Is the ACA perfect? No, not quite. I don’t believe there is a perfect preamp, but the ACA came scaringly close.

Compared to a perfectly matched impedance passive preamp, the ACA losses a little bit of clarity. No, I am not talking about a typical passive preamp. The ACA put the Audio Synthesis Ultimate Passive to shame.

What I am talking about, is a passive preamp that was custom built, with very best parts, and designed to work with known set of equipment. However, the ACA beat the passive preamp in dynamics.

I did compare the ACA to a number of tube preamps including the well-known BWS-Tube. The ACA was a head and shoulder above all the tube preamps that I have heard and built.

There are a few things I wish the ACA had:

a) It does not have remote control. A lot of people saying that remote-controlled preamps sacrifice sound because most remote volume control pots are low quality. It is possible to implement remote controlled ladder stepped attenuator. However, it is expensive, and nOrh would have to raise the price of the ACA substantially for it to have this feature. The Audio Synthesis Ultimate Passive is an example of remote-controlled stepped attenuator and it retails for $ 2000.00.

b) The ACA has a phono input, a video bypass input and three normal inputs. This is not enough for my setup. I don’t have a turntable so phono-input is useless. The video bypass is great for me to combine home theater and music. The remaining three inputs are not enough for my CD, DVD, DSS, Tuner, and VCR.

Consider the price tag of the ACA, I must say that the ACA has no weakness at all. Is the ACA a giant killer preamp? I believe it is. I am fairly sure that there are better preamps out there but at a much higher cost. It already beat the Proceed Pre (MSRP $ 2000.00) the Plinius 8200 (MSRP $ 3000.00) and the BWS-Tube Preamp ( MSRP $ 3500.00 direct sale), and to me it deserves the giant killer honor.



Disclaimer: I have no relationship with nOrh other than being one of their customers. The review was done in my house with my equipment, and these are my opinions of the ACA so take it with a grain of salt.

Associate Equipment:
Proceed Pre Preamp
Plinius 8200 Integrated Amp with Pre-Out
Custom built tube preamps.
Custom Built Passive Preamp
BWS-Tube Preamp
Audio Synthesis Ultimate Passive
nOrh CD1 CD Player
A pair of nOrh Multiamp in mono block configuration
A pair of marble nOrh 9.0
nOrh Silver Interconnects
nOrh Silver Speaker Cable
Power Wedge 116 MK II
Harmonic Technology AC-11 Power Cord.

Expand full review >>

Used product for:   1 to 3 months

Duration Product Used:   Audio Enthusiast

Product model year:   2000

Price Paid:    $900.00

Purchased At:   Directly from nOrh



Overall Rating:5
Value Rating:5
Submitted by RobC a Audio Enthusiast

Date Reviewed: January 16, 2001

Bottom Line:   
Background on me: I started this hobby by way of HT. I set up my main system with Klipsch speakers and Pioneer Elite receiver. I started to listen to more music than I did watching movies. I didn’t like the sound of the Klipsch’s for music and went back to the high end store to listen to speakers. I ended up buying B&W601 s2 speakers for a second HT system in my family room. About this time I heard about AH! Tjoeb CD players and ordered one. I liked it so well, I ordered another.
While I was researching the B&W 805 speaker here I came across a review that said if you like the N805, look at the nOrh speakers. I did and I liked what I saw. Since I had a positive experience ordering direct with the AH! CDP, I took the chance and I bought a pair of wood 7.0’s. About three weeks after they arrived I sold my Klipsch’s and haven’t looked back.

I hooked up the ACA and turned on the CD player and immediately it sounded better then the Morrison ELAD pre-amp that I had previously been using. It sounded cleaner then anything I had ever heard before. The holographic nature of the music was something that I had not experienced before. I mean stereo imaging and sound staging sure, but I am talking about Cassandra Wilson in a 3D hologram behind my equipment rack singing Sweet as Tupelo Honey! She was there, not her voice, but her!

What I noticed was that with the Morrison there was background noise or hash, I never knew was there until it was gone. I don’t know if the ELAD added the noise, or if the ACA gets rid of it. Either way I don’t care. Prior to this I thought that the Morrison was the most revealing and transparent pre-amp, and it might have been, but the ACA just takes my music to another level.

I use the video pass through so I can use my two channel speakers as my front left and right in my HT system. They have never sounded so cohesive. Front left, center and right are all the same speaker (marble nOrh 9.0’s) I have heard cymbals and brush strokes in DVD’s that I had never heard before (listen to Two Against Nature) .

Like the previous poster it is hard to get the smile from my face.

I have never heard a better pre-amp, and I have never heard a better audio system.

I don’t use the phono stage, but I have used the headphone output with my Sennheiser HD 600’s. These are hard to drive headphones and the ACA made them sound great. I did have to turn up the volume knob past where I usually have it playing through my speakers, but it still had plenty of room left.

Highest recommendation for overall quality, and at $900 an absolute steal!

From my equipment you can assume that I find nOrh products to not only be the highest quality, but also the best value.

Current system:
nOrh ACA preamp
nOrh multi-amps in “active mode
Front speakers are nOrh marble 9.0’s , front left and right sit on nOrh subs, center sits on TV
Rear speakers soon to be nOrh ceramic 4.0’s (currently Klipsch s6’s)
nOrh CD1
Toshiba 71” HDTV
2 Hsu 1225 subs powered by Hsu 500w amp
Pioneer Elite VSX 27TX receiver
Toshiba 2109 DVD
PS Audio PP600 power generator

Expand full review >>

Used product for:   Less than 1 month

Duration Product Used:   Audio Enthusiast

Product model year:   2000

Price Paid:    $900.00

Purchased At:   www.norh.com




Reviews 1 - 5 (7 Reviews Total) | Next 15

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