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Apt Holman Preamplifier Review (vintage Audio)

PeteL

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Great stuff, I used to be much into vintage gear and still have today a few nice units that I chose to keep although they are not in my daily system, but the key word here is: Refurbished. That's the main thing, getting into vintage is fun, but no one should buy 40 years old stuff thinking they will save money and get a deal. Here's the news, none will be proper and up to specs. If a tech tells you he will refurbish it for 200$, you can tell right away he is not serious, when you see a piece of gear being advertised for 300$ with the mention .just have been restored by a technician. It's not true, He probably just cleaned it with deoxit and checked that a sine at the input give sort of a sine at the output. These things need love, need time, need proper measurments and testing, Ideally a close to full recap. It takes time, it's not cheap and rightfully so, when you do business with someone who know what he is doing. Vintage is great, but it's not financially sound, you do it for the love and we should. It is sad to see great engineering go to the trash bin, I give much kudos to those who care, but buying older gear will cost you more than the equivalent in modern gear, and it should, those techs need to be paid well for the service they do to Hifi.
 

Frank Da Si

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I still own mine since new and did a refurb last winter. Being OCD I probably went overboard but is sings along nicely with the Bryston and DCM Time Windows.
One cannot find the same functionality today let alone the number of inputs at a reasonable price.
 

617

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Better feature set than many modern preamps. I really wish Topping would make something like this.
 

Frank Da Si

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Et voilà mon bébé.
 

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pjn

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This is a review and detailed measurements of the Apt Holman vintage preamplifier. It is on kind loan from a member and has been refurbished by QuirkAudio.

The look is a cross between hifi and pro gear:

View attachment 167044

Other than some scratches on top, the unit is a very good cosmetic shape. Rear connections are extensive:

View attachment 167045

Yes, there was a time we had outlets in the back of stereos. The more there was, the higher end the gear was said to be! Wonder what led to their demise.

In case you are wondering as I did when I was first contacted about this unit, Holman is Tomlinson Holman or the T in THX (now works for Apple). Owner sent me the service manual which is not only extensive but has excellent tutorials on the design, instruments to test it with, and pages and pages of detail. It is incredible what used to be available compared to now.

Apt Holman Measurements
Let's start with our dashboard input. I selected Tape 1 as input but oddly front panel selector doesn't have Tape 1. I set it to Aux 1 and then pushed Tape 1 switch:

View attachment 167047

Wow, this is excellent! I expected SINAD in 60s or 70s and here we have 90 dB. It is dominated by second harmonic at that level. Even more impressive is the signal to noise ratio with same unity gain:
View attachment 167048

Frequency response was dead flat in audible band:
View attachment 167049

Crosstalk is better than many devices I test today:

View attachment 167050

There is essentially no frequency dependency in distortion+noise:

View attachment 167051

Output level is optimized for about 0.4 volts or so:
View attachment 167052

So you may want to pair it with a power amplifier that puts out most of its power at the above level.

Apt Holman Preamplifier Phono Stage Measurements
I adjusted the volume control to give a nominal 40 dB level (higher than preamp tests):
View attachment 167053

While I like to see no visible distortion spikes in this test, its level at -100 dB is still very good. SINAD is set by the slight amount of mains noise which I could not get rid of with various grounding methods (typical).

RIAA equalization is very good but there seems to be a high frequency resonance that causes error above 10 kHz:


View attachment 167054

I did not look to see if there is an adjustment/compensation for this in the service manual.

Be sure to use the balance control to restore equal level in both channels.

Level of headroom is good:


View attachment 167055

And doesn't change a lot due to frequency:
View attachment 167056

Conclusions
The owner who sent me this has a knack for finding these past jewels with excellent engineering. Their performance post refurbishing is extreme good even by today's standard which sadly has sled backward. Hopefully no one sheds a tear next time I complain about an audio product producing SINAD of 70 dB and such which this level of performance was achieved years ago.

I am happy to recommend the Apt Holman preamplifier. I see one on ebay for $550 although it will likely need thorough service like the sample I tested.


----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Like you, I really miss those outlets on the back. That's a really nice amp, although the channel imbalance is curious, but easily corrected. Really good S/N ratio for the time
 

JeffS7444

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In the early 1980s, a nice secondhand Apt amp and preamp, and even a complete Technics SL1000 turntable setup appeared at a dealer I frequented, and I was interested but was told "don't bother, they're nothing special" :facepalm:
 

Digital Mastering System

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I got one last year and intend recap and chip roll. The Apt-Holman is stuffed with TLO72s, while not bad, are certainly not state of the art. It also has several emitter followers in the signal path which probably limit the distortion to what is seen in this review. Amusingly, the preamp had a couple of spare opamps left over, so the designers used them in the output stage, configured as a negative resistance load. I think it compensates for the output stage's feedback load. At any rate, chip rolling to OPA1656 and OPA2156 will be a big upgrade.
 

Mosquito

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This is a review and detailed measurements of the Apt Holman vintage preamplifier. It is on kind loan from a member and has been refurbished by QuirkAudio.

The look is a cross between hifi and pro gear:

View attachment 167044

Other than some scratches on top, the unit is a very good cosmetic shape. Rear connections are extensive:

View attachment 167045

Yes, there was a time we had outlets in the back of stereos. The more there was, the higher end the gear was said to be! Wonder what led to their demise.

In case you are wondering as I did when I was first contacted about this unit, Holman is Tomlinson Holman or the T in THX (now works for Apple). Owner sent me the service manual which is not only extensive but has excellent tutorials on the design, instruments to test it with, and pages and pages of detail. It is incredible what used to be available compared to now.

Apt Holman Measurements
Let's start with our dashboard input. I selected Tape 1 as input but oddly front panel selector doesn't have Tape 1. I set it to Aux 1 and then pushed Tape 1 switch:

View attachment 167047

Wow, this is excellent! I expected SINAD in 60s or 70s and here we have 90 dB. It is dominated by second harmonic at that level. Even more impressive is the signal to noise ratio with same unity gain:
View attachment 167048

Frequency response was dead flat in audible band:
View attachment 167049

Crosstalk is better than many devices I test today:

View attachment 167050

There is essentially no frequency dependency in distortion+noise:

View attachment 167051

Output level is optimized for about 0.4 volts or so:
View attachment 167052

So you may want to pair it with a power amplifier that puts out most of its power at the above level.

Apt Holman Preamplifier Phono Stage Measurements
I adjusted the volume control to give a nominal 40 dB level (higher than preamp tests):
View attachment 167053

While I like to see no visible distortion spikes in this test, its level at -100 dB is still very good. SINAD is set by the slight amount of mains noise which I could not get rid of with various grounding methods (typical).

RIAA equalization is very good but there seems to be a high frequency resonance that causes error above 10 kHz:


View attachment 167054

I did not look to see if there is an adjustment/compensation for this in the service manual.

Be sure to use the balance control to restore equal level in both channels.

Level of headroom is good:


View attachment 167055

And doesn't change a lot due to frequency:
View attachment 167056

Conclusions
The owner who sent me this has a knack for finding these past jewels with excellent engineering. Their performance post refurbishing is extreme good even by today's standard which sadly has sled backward. Hopefully no one sheds a tear next time I complain about an audio product producing SINAD of 70 dB and such which this level of performance was achieved years ago.

I am happy to recommend the Apt Holman preamplifier. I see one on ebay for $550 although it will likely need thorough service like the sample I tested.


----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
apart the whole ton of goodies on this preamp, playing with the stereo narrow/wide knob must be a lot of fun
 

DonH56

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I loved the Apt Holman preamp! Place I worked back then sold them, and the Apt Holman amplifier as well. It was always underrated in my mind, sandwiched between things like the Hafler and high-end Mark Levinson stuff. IIRC it was quieter than the ML preamp and had better performance. And had cool little features like phase inversion and the image knob.

Small world moment: I spent some time talking with his son many years ago about a possible job (in bioengineering, not audio). Didn't take the job, but it was neat talking with him.
 

Joe Smith

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This was on my "do want" list for a long time. Such a cool unit and I love the history of them. Just don't have much need for separate Pre's right now and of course they do need a good going through to sound as good as in 1980. Delighted to see that they can be restored to this level of performance. My better of my two Pre's is a Nikko Beta 20, which has very good internals and I hope I someday find a good place for her and then could justify a restoration...
 

Dan Clark

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1979 this thing exceeds the performance of any consumer media aviable at the time ?
And loudspeakers of that era how good where they.
At the time this would have been “transparent” to the end user . And probably still is today in most cases
At that time I had a dual mono Hafler 220 with Vandersteen 2c speakers and an Oracle turntable. You could get amazing sound, actually, amd then the first gen of horrible sounding CD players kinda played havoc with the 2 channel world.
 

LTig

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I got one last year and intend recap and chip roll. The Apt-Holman is stuffed with TLO72s, while not bad, are certainly not state of the art. It also has several emitter followers in the signal path which probably limit the distortion to what is seen in this review. Amusingly, the preamp had a couple of spare opamps left over, so the designers used them in the output stage, configured as a negative resistance load. I think it compensates for the output stage's feedback load. At any rate, chip rolling to OPA1656 and OPA2156 will be a big upgrade.
Do we know what type of opamps the tested preamp has?
 

david moran

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Me too. I am familiar with all of them. :D
Just some misc comments from one who was there then:

- ac jacks on the back of components disappeared as a cost thing, at least at most manufacturers; doubtless there were tweak articles saying they degraded something or other

- Jpn speakers were awful then and not much better afterward; I was interviewed by the WSJ about it and had to say 'No one knows why'

- American speakers, some of them, were and remain superb --- Allisons, dbx Soundfields, AR, some BA, some Advent, some ADS, some CV, the occasional Bose, no JBL at the time, and of course there are hosts of others. Brit speakers were improving, with Kef, not B&W, leading the way eventually. (It took them forever to understand that in an enclosed space what we hear from a speaker system IS its radiation pattern, something known in this country for decades but seldom stated explicitly because never needed to.)

- Some companies that mimicked Apt appearance, and attempted to do simulate performance, were run by people who knew one another and knew Holman (we were pals, most of us, at least in the Boston area as members of the BAS, including the many eminent audio journalists) --- Victor Campos at Adcom and sometimes NAD, others at NAD, various engineers at ADS, and others. Advent hardware, and before them AR (Allison designs largely), like Dynaco, all were function-->form for the most part. But the Crown and Hafler too, being run by engineers. The superb dbx CX1 was explicitly designed to duplicate and slightly surpass (even in noise spec) this Apt, but, you know, inexpensive NAD and Adcom preamps came v close eventually.

- not sure the phono settings were correct for load?

The Holman work was done in the 1970s and carried into the 1980s and a bit beyond, before audio and its market began to change so drastically.
 
Last edited:

EJ3

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Just some misc comments from one who was there then:

- ac jacks on the back of components disappeared as a cost thing, at least at most manufacturers; doubtless there were tweak articles saying they degraded something or other

- Jpn speakers were awful then and not much better afterward; I was interviewed by the WSJ about it and had to say 'No one knows why'

- American speakers, some of them, were and remain superb --- Allisons, dbx Soundfields, AR, some BA, some Advent, some ADS, some CV, the occasional Bose, no JBL at the time, and of course there are hosts of others. Brit speakers were improving, with Kef, not B&W, leading the way eventually. (It took them forever to understand that in an enclosed space what we hear from a speaker system IS its radiation pattern, something known in this country for decades but seldom stated explicitly because never needed to.)

- Some companies that mimicked Apt appearance, and attempted to do simulate performance, were run by people who knew one another and knew Holman (we were pals, most of us, at least in the Boston area as members of the BAS, including the many eminent audio journalists) --- Victor Campos at Adcom and sometimes NAD, others at NAD, various engineers at ADS, and others. Advent hardware, and before them AR (Allison designs largely), like Dynaco, all were function-->form for the most part. But the Crown and Hafler too, being run by engineers. The superb dbx CX1 was explicitly designed to duplicate and slightly surpass (even in noise spec) this Apt, but, you know, inexpensive NAD and Adcom preamps came v close eventually.

- not sure the phono settings were correct for load?

The Holman work was done in the 1970s and carried into the 1980s and a bit beyond, before audio and its market began to change so drastically.
I started with the ADVENT 300 receiver (Henry Kloss & Tomlinson Holman) with a Connoisseur TT, & Frazier Super Monte Carlo speakers (all Frazier speakers were high efficiency speakers). Jack Frazier (With his partner, Ed May, Jack Frazier began manufacturing loudspeakers ca. 1954 in Dallas, Texas. The company was known as "Frazier-May" until May took a position with JBL in 1956, at which time the name was changed to Frazier. From that time through the 1970s, Frazier offered consumer hi-fi speakers in addition to its primary line of commercial products. The company operated under Jack's leadership until his death in 1983) was about the only guy in Audio that Paul Klipsch associated with (& they were friends & had similar, yet different, ideas about speakers. Later, I went to the Apt/Holman Preamp. Eventually I added NAD 2100's to the ADVENT 300 (which is now it's own system with the Fraziers), and NAD 2200's to the APT/Holman Preamp. Then a Dual 1229 TT, a second APT/Holman & a Technics SL-M3. Some more NAD 2200's, some AKai RTR's, some near TOTL Kenwood & JVC cassette decks & a NAD 4300 tuner. There have been various CD players, from my first MAGNAVOX/Philips (very good), my next SONY carrousel (terrible) to my now SONY RCD-500/W-100 (20 bit perfect). I can send from my computer to the main APT/Holman system Bluetooth through a BluDento BLT-HD and am using Dahlquist M-905's with custom subwoofers. I have kept all this stuff & it works good enough for me.
Also oppo 205 UHD & can send into the system from my computer
 

KEFCarver

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Hit and miss. There where North American made speakers and Euro too and such that where pretty good. Some even sound decent today. But the Japanese speakers generally cranked pretty loud and thumped well but the top end was usually lacking.

EDIT: Here is a very popular Kenwood speaker of the time. Expensive and often peeps bought 4 of them.
Kenwood_KL-777_Stereo_Speakers_web.jpg

Another perhaps a bit higher model.
8ec344c9c670c61b663e5d8dce1db18f.jpg

Cerwin Vega was popular then too.
9SrCIEY.jpeg

Vintage-1978-Pair-Cerwin-Vega-S1-Loud-Speakers.jpg

REFERENCE SERIES MODEL 105 (1977-79) These KEF 105 and 5.2 are nice speakers even today.
First-References22.jpg

gkuA_-tDtgbgXVK0_bJFM1e4Gk1xNt8ko11YeJiCRM2U8swWWHdvMJuyX5BoMLibEaz7CLV6pPbJa6yf4T0Fe2aGfi0SWecMwqOHXSXhNyO9qqQU7jJyS3shPbsiTjbMR830
Ahh, the good 'ol days!
 

AudioTodd

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This was (and is) a truly excellent preamp that, teamed with a Hafler amp and various input devices, constituted my stereo system for many years. Until my ex- took it to spite me in the divorce. Sigh.... :)
My buddy's Dad had one with a DH200 and Magnepan speakers fed by a Dual TT, a R-to-R (Akai??) and Aiwa cassette deck (my Nakamichi was better but being a kid I couldn't talk trash with him) which pretty much introduced me to "high end" audio!!! Unfortunately the Maggies were not well placed and were paralleled with Cizek Model 2s over 50-100 feet of zipcord to his office. I used to house sit for them and the first thing I would do when they left was move the Maggies and disconnect the Cizeks!!!
 

Chrispy

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I started with the ADVENT 300 receiver (Henry Kloss & Tomlinson Holman) with a Connoisseur TT, & Frazier Super Monte Carlo speakers (all Frazier speakers were high efficiency speakers). Jack Frazier (With his partner, Ed May, Jack Frazier began manufacturing loudspeakers ca. 1954 in Dallas, Texas. The company was known as "Frazier-May" until May took a position with JBL in 1956, at which time the name was changed to Frazier. From that time through the 1970s, Frazier offered consumer hi-fi speakers in addition to its primary line of commercial products. The company operated under Jack's leadership until his death in 1983) was about the only guy in Audio that Paul Klipsch associated with (& they were friends & had similar, yet different, ideas about speakers. Later, I went to the Apt/Holman Preamp. Eventually I added NAD 2100's to the ADVENT 300 (which is now it's own system with the Fraziers), and NAD 2200's to the APT/Holman Preamp. Then a Dual 1229 TT, a second APT/Holman & a Technics SL-M3. Some more NAD 2200's, some AKai RTR's, some near TOTL Kenwood & JVC cassette decks & a NAD 4300 tuner. There have been various CD players, from my first MAGNAVOX/Philips (very good), my next SONY carrousel (terrible) to my now SONY RCD-500/W-100 (20 bit perfect). I can send from my computer to the main APT/Holman system Bluetooth through a BluDento BLT-HD and am using Dahlquist M-905's with custom subwoofers. I have kept all this stuff & it works good enough for me.
Also oppo 205 UHD & can send into the system from my computer
Forgot about that the Kloss/Holman team for Advent....

So what kind of going thru did the pre-amps need that Amir referred to? Who performed it?
 

EJ3

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Forgot about that the Kloss/Holman team for Advent....

So what kind of going thru did the pre-amps need that Amir referred to? Who performed it?
I have been doing preventative maintenance & upgrades on my ADVENT 300, 2 NAD 2100's (while the results are good, they are not worth the effort & expense [you can have both better results & less expense with NAD 2200-2700 series of amps]), 5 NAD 2200's & 2 APT HOMAN Preamps every 5 to 10 years or so (it depends on what comes along in the upgrade scene & whether it is worth the expense). I usually wait on upgrades to do at the same time as the general maintenance. The past several times I have used Peter Williams of QuirkAudio. (https://quirkaudio.com/). There are others (particularly if you need original parts such as faceplates, rack mount faceplates, etc: PM me if you need that kind of thing [I do not have those type of items but I can direct you to some folks that do, some of which is NOS]).
 

restorer-john

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Better feature set than many modern preamps. I really wish Topping would make something like this

They never would unfortunately. The feature set is pretty much normal to us older guys, but it would be a tough sell to people these days.

No need for bi-directional tape dubbing or alternate tape monitoring (no three heads decks to worry about). Tuner? Who uses one these days? Two turntables?- most people have none. And no hipster is going to waste time with measuring responses with different cartridge loading like we did.

The Holman's performance is good, not excellent and certainly not state of the art in the late 1970s, letalone now. But it is riddled with a cascade of circuit elements as it was clearly designed as individual optimised components, not as a holistic preamplifier from end to end. It's circuit design is reminiscent of an old skool tube preamp, with more coupling capacitors than I have ever seen from source to output in one product. No wonder its low end repsonse is as poor as it is.

Even in the most direct route, we have nine (9) coupling caps from phono to line outs.

The phono overload is very disappointing on this Holman, it's rated at over 100mV and we see a 1kHz overload at a paltry 80mV. Sure 100mV can be achieved at 1%, but there were plenty of preamplifiers out there with 300-400mV overloads at the time.
The frequency response should be ruler flat, but it just cannot be with the design. We see rolloff commencing at 200Hz.

I like the TI TL-072 Jfet opamps, even if they are run right on their max voltage edge, they are a classic and it's pretty amazing to see the entire preamp is run from a single pair of regulators uA-7818/7918 (+/-18V). No fancy individual channel discrete regulated supplies here- it's about as cheap and simple as you could get. And yet it works pretty well.

I really wish someone in the US close to Amir could send him the old Japanese classics of the same era, such as the Yamaha C-2/2a/2x, Denon PRA-1000/2000/3000, Kenwood LO-7c/7cii, Sony TAE-86/86B, Technics SU-9070/9200/9600 etc. Surely some of you guys have some in your collections?
 

LTig

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I like the TI TL-072 Jfet opamps, even if they are run right on their max voltage edge, they are a classic and it's pretty amazing to see the entire preamp is run from a single pair of regulators uA-7818/7918 (+/-18V). No fancy individual channel discrete regulated supplies here- it's about as cheap and simple as you could get. And yet it works pretty well.
According to quirkaudio a refurbed preamp gets new ICs, so I expect that in the tested unit those TL072 have been replaced by something more modern. With a +/-18V supply voltage I would chose a model like the OPA2604 which is rated for +/- 24 V to have some reserve.
 
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