Apt Holman Preamplifier Review (vintage Audio)

[rdenney]

I'm with you on this. Is it that unusual for an audiophile to have or want a streamer, cd player, tape deck and a turntable?

A preamp should be flexible and have lots of functionality with a great interface. Audio performance is secondary, but only because perfection should be almost trivial.

I think what this review shows is how close we could come to perfection even decades ago. We have long-since been left with mystical imaginings to provide any differentiation in audio performance, assuming basic competence. But a preamp without the necessary features (which include--for those who desire LP playback--the ability to tailor the phono preamp to the squirreliness of the cartridge) won't be used in my system no matter how many dB of SINAD it provides above my ability to hear it.

Rick "close enough for my ears" Denney

 

[EJ3]

I think in addition...

This pream has a very clean sounding and capable headphone amplifier inside.

As headphone listening has also become common for many people, the Apt Holman seems a good choice as a center for an all around system without having to add several other separate components cables and such related ancillaries.

1 Apt Holman preamp can do a high quality job substituting...

1 line stage stereo preamplifier
1 line stage mono preamplifier
2 phono preamplifiers
1 headphone amplifier
1 18v dc power supply for an additional equipment. I have a DACT phono preamp wich runs on 18v dc, I can hookit up to the Apt and have a 3 phono capable preamp.

I am very satisfied with the sound queality on my updated Apto Holman preamp. Although I can not attest to how it compared to other preamps of the era, I can vouch the the high sound quality of the unit I acquired.

I am using one of the lines in on mine for a computer Blue Tooth input though a Blue Tooth transceiver (so that when I get better setup with record (RIP< whatever) to my computer. But currently I can play anything from my computer which is upstairs with a wall or 2 & 45 ft away between the stereo downstairs that has both my APT/Holman's as it's Preamps.

 

[Thermionics]

FWIW, I use my APT Holman preamp with a Raspberry Pi / Topping D90 digital source + a pair of DIY Pass ACA amps (yes, yes, I know), a Parts Express Titan 10" subwoofer and Linaeum LFX speakers in a nearfield configuration for my home office. Makes 10-12 hour workdays much more pleasant.

 

[yoyoc]

So... What would you comment about the Apt / mono ACA's / Lineum tweeters -speaker combination?
I know those are almost 360° tweeters.

 

[mglobe]

The secret sauce with the Apt is how well it can be mated to a wide variety of cartridges, how good the RIAA equalization is, how flexible it is, and how good the SINAD is. I don’t see what is downstream of it being something to worry about. It will work. Mine feeds into a MiniDSP Flex where I do room correction with Dirac. Nice combination of vintage and new.

 

[yoyoc]

The secret sauce with the Apt is how well it can be mated to a wide variety of cartridges, how good the RIAA equalization is, how flexible it is, and how good the SINAD is. I don’t see what is downstream of it being something to worry about. It will work. Mine feeds into a MiniDSP Flex where I do room correction with Dirac. Nice combination of vintage and new.

Precisely Ive been thinking of including a mini dsp for DIRAC room correction in the processor loop of the APT...

Can you comment your experience with that?

 

[mglobe]

Precisely Ive been thinking of including a mini dsp for DIRAC room correction in the processor loop of the APT...

Can you comment your experience with that?

I’m a neophyte with Dirac, but I very clearly helped tame my room modes. I have three different profiles I toggle through, never quite sure which one I like best. I’ve learned a fair amount since I first set it up, and plan to re-do it in the near future.

I output from the Flex to my Audiophonic monoblocks, and do the cross over to my subs in the Flex. The Apt only gets used as a phono pre. The flex selects the input (Apt, and Roon Server) but that is clearly not the only way to do it. I have owned the Apt since about 1980, and had Quirk Audio refresh it.

 

[yoyoc]

I’m a neophyte with Dirac, but I very clearly helped tame my room modes. I have three different profiles I toggle through, never quite sure which one I like best. I’ve learned a fair amount since I first set it up, and plan to re-do it in the near future.

I output from the Flex to my Audiophonic monoblocks, and do the cross over to my subs in the Flex. The Apt only gets used as a phono pre. The flex selects the input (Apt, and Roon Server) but that is clearly not the only way to do it. I have owned the Apt since about 1980, and had Quirk Audio refresh it.

Thanks for the response

Why did you choose the flex and not other of the mini dsp models?

 

[mglobe]

Thanks for the response

Why did you choose the flex and not other of the mini dsp models?

Cost + features. If I were to do it again, I might go with the SHD, as it is Roon ready. I use a MS Surface Dial through a Roon extension to control volume when I listen to Roon. If i had the SHD, I could also control volume when I’m listening to records. But that’s not much of a justification for the extra spend. The flex gives you analog and digital in, does ADC, sub Xover, Dirac correction, and analog output to amps and subs.

 

[EJ3]

Indeed I read them all, also the review at Kenrockwell, some discussion at other forums ( including Steve Hoffman's where there are also some comments aby another gentleman who also worked at the Apt manufacturing who goes by the handle of R. Totale) and read Audio Mag. 1980 review. Also had a lengthy phone conversation with Vince before ordering.

My analog rig consists mainly of a Well Tempered "original square motor" turntable with a Sumiko SHo high output mc and a Well Tempered Amadeus GTA turntable with a Dynavector XX2 low output mc. Both tables have low mechanical noise due to their main bearing and have no ball bearings at the tonearm pivot. Their combination with the Apt Holman is very telling about how low is the noise of the preamp, the quality of their mm and mc phono eq and its neutral sound.

Conversations with Vince are always interesting to me. Years ago when I was lived out of the USA for 17 years (Saipan & Islands/Atolls in the Indian Ocean & Oceana in the Western Pacific), we had a number of conversations and he did some wonderful work for me on my ADVENT 300, some APT/Holman Pre's & an NAD 4300 tuner. He is the only person that I know personally that can properly align an FM tuner (that is not to say that there are not others, just that he is the only one that I know that can do a damn good job of it).

 

[EJ3]

So... What would you comment about the Apt / mono ACA's / Lineum tweeters -speaker combination?
I know those are almost 360° tweeters.

I have had Lineum tweeters as part of my setup in the past. But that was not with my APT/Holman Pre. I can only say that they are different, not better, not worse. I think that the room that you have them in & where you place them has as much to do with how you like them as anything else.

 

[Thermionics]

Part of the magic of the Linaeum LFX (first generation) is the use of the Vifa P13-WH-08-08 5" mid-woofer. I'm not using the speakers in a way that really can take advantage of the dipole aspect of the tweeter, but given this is near-field while I work, I don't mind terribly.

 

[EJ3]

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.

There is an adjustment in the service manual for this. Also the rise above 10 KHz in the phono section (in both my units) is due to someone having removed a resistor.
Both of these things will hopefully be rectified at some point when these go in for servicing after Jan 1 of 24 (not sure, when, there are a few other things in front of them).

 

[NormB]

There is an adjustment in the service manual for this. Also the rise above 10 KHz in the phono section (in both my units) is due to someone having removed a resistor.
Both of these things will hopefully be rectified at some point when these go in for servicing after Jan 1 of 24 (not sure, when, there are a few other things in front of them).

Seriously? JANUARY ‘24?

I called last week, am awaiting a return call about mine, I’d like to get the level 3 treatment for it, but JANUARY?

 

[NormB]

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/

Thank you for this, Amir.

I’ve been reading about these preamps for years but every time I’d see one on ePay or the audiomarts the price was, for me, absurdly high.

So I’ve been buying, refurbishing/upgrading and selling ADCOM stuff for about five years, settling on a pair of GFP-565’s I’ve done power supply and opamp rolling with along with the usual Big Sky tweaks found online and have been VERY happy with the results so far.

Then I found a good deal on an APT Holman preamp about a month ago ($250 delivered) and got around to playing with it maybe 2 weeks ago.

Wow.

I thought the 565’s were good, esp. with OPA604 preamps in gain section, recapping with Nichicon UKA (another with UFG, although I prefer the UKA’s) but the clarity, the finer details in things like stick articulation on cymbals, snare drum resonance that I can pick out of music I’ve listened to hundreds of times since the late sixties and I
never really heard that detail until NOW.

TT is Thorens TD 125 Mk II, cartridge Benz Micro Glider SL, TA SME V (recently updated by SME Canada), fed into a Quadratic SUT I run into the cartridge inputs - also using a Cambridge Audio CD player and Topping D90 DAC. REVOX B77 II as well. Amps are either (upgraded) ADCOM 545-II or (highly upgraded) Willsenton R8 tube amp into Klipsch Synergy IV speakers (or 45 year old Ohm-Walsh 4’s with 5 year old drivers).

This setup works for me so far. Mostly, but the only thing I think would make a YUGE difference is an Ortofon Cadenza Black cartridge Ihave on hand but have only “auditioned” so far, and maybe a higher quality tube amp, or just better output transformers in the R8.

And for all of you who are dying to jump in with “YOU SHOULD BUY…” thanks, but I’m Retired. Medically disabled veteran. My former BFF I knew since 8 years old absconded with my entire 401k (and several other people’s) a few years back so I’m on a fixed income, and do what I can to get better audio gear when and how I can one or two pieces of gear a year. What I’d LIKE is a newer pair of German Physiks ultra graphite or whatevers, but $10k (used) is WAY out of my budget right now. I’d like my tinnitus to go away too, but that’s another story…

I had been thinking lately of finding a good used ADCOM GFP 750 but now the prices on THOSE are absurdly high (a grand? Their NEW 915 costs that much and I’ve had TWO of them which were DOA) and I can’t believe I’d be investing wisely in one when I can send this APT in for upgrades, recapping/tuneup for a lifetime of listening pleasure.

This has been a good post to read through for me. Seems like I’ve made a good choice here.

Thanks again.

 

[EJ3]

Seriously? JANUARY ‘24?

I called last week, am awaiting a return call about mine, I’d like to get the level 3 treatment for it, but JANUARY?

Seriously? JANUARY ‘24?

I called last week, am awaiting a return call about mine, I’d like to get the level 3 treatment for it, but JANUARY?

The one that was tested here is one of my 2. I got my second one (with the max that he does done on it) from Vince at Audio Proz (in Massachusetts) many years ago. The level 3 treatments on the APT/Holman Preamps are long behind me.
Since then I have had other work done, first on my NAD 2100 & then on my NAD 2200's & then on my APT/Holman Preamps (as I was sending them from the Western Pacific) by Peter Williams of Quirk Audio (in California), as it was closer to where I was at (Saipan). The APT/Holman's both have the same mods, after having been through both Vince & then years later, Peter. Yes, the one that went through Amims hands had both.
I was very lucky, as it turned out that Peter is very, very, good, also.
I will also be making another purchase from Vince in January 24.
Now I am on James Island, SC.
In 5 year rotations, (scheduling a couple of items every year or so, I send my vintage (?) gear out for inspections, updates (if their are any), etc..
By the way, if you need a TUNER alignment (in either a separate TUNER or a RECIEVER, VINCE at AUDIO PROZ is the only one I know that is great at that. (there certainly may be others, but he is the only one that I have experience with on performing that function & the result is fantastic.
As to my length of timing: Someone's car cut across in front of me and I hit them at about 49+ MPH. My wife's vehicle was destroyed. Their insurance company agreed with the Police report & accepted 100% liability. I cannot even lift a #10 can of something at the moment. My wife is in a hospital overseas. And my audio budget for this year is done. (also the fact that I cannot pack any gear & get it to the shipping place, at the moment, has something to do with it, even if my wife was here & I still had money in my audio budget. So, yes, January, 24: 6 months from now, when I retire & start receiving an annual stipend (which will increase my annual audio budget a bit). In January every year.

 

[NormB]

The one that was tested here is one of my 2. I got my second one (with the max that he does done on it) from Vince at Audio Proz (in Massachusetts) many years ago. The level 3 treatments on the APT/Holman Preamps are long behind me.
Since then I have had other work done, first on my NAD 2100 & then on my NAD 2200's & then on my APT/Holman Preamps (as I was sending them from the Western Pacific) by Peter Williams of Quirk Audio (in California), as it was closer to where I was at (Saipan). The APT/Holman's both have the same mods, after having been through both Vince & then years later, Peter. Yes, the one that went through Amims hands had both.
I was very lucky, as it turned out that Peter is very, very, good, also.
I will also be making another purchase from Vince in January 24.
Now I am on James Island, SC.
In 5 year rotations, (scheduling a couple of items every year or so, I send my vintage (?) gear out for inspections, updates (if their are any), etc..
By the way, if you need a TUNER alignment (in either a separate TUNER or a RECIEVER, VINCE at AUDIO PROZ is the only one I know that is great at that. (there certainly may be others, but he is the only one that I have experience with on performing that function & the result is fantastic.
As to my length of timing: Someone's car cut across in front of me and I hit them at about 49+ MPH. My wife's vehicle was destroyed. Their insurance company agreed with the Police report & accepted 100% liability. I cannot even lift a #10 can of something at the moment. My wife is in a hospital overseas. And my audio budget for this year is done. (also the fact that I cannot pack any gear & get it to the shipping place, at the moment, has something to do with it, even if my wife was here & I still had money in my audio budget. So, yes, January, 24: 6 months from now, when I retire & start receiving an annual stipend (which will increase my annual audio budget a bit). In January every year.

SO sorry to hear about the injuries.

Mine - some, anyway - originated with getting rear-ended while on a motorcycle, active duty Army, returning from visiting friends at a military hospital with pricey pharmaceuticals jammed in my coat (courier run as a pharmacy tech in ‘79) at 1130PM. Drunk driver (BAT 0.43% - she was a pro), cop witnessed accident. Was in PT for most of 2 years and off-on since. They tell you when you’re 20 you’ll heal. Yeah. Then there was mefloquine I took for malaria prophylaxis while in SE asia ‘92 and ‘93 (MIA-POW missions with JTF-FA) which left me with sensorimotor neuropathy affecting just about everything.- gait, balance, coordination, gut motility, more.

It adds up. Partial 20% VA disability since ‘83, 90% past 5 years, 100% this year. Then I started on social security last year. I haven’t worked for 18 months and it’s hard to get used to. Listening to music helps with the tinnitus; got into a waitlist for some new treatment (Lenire?) I’m looking forward to.

Audiology eval 2 weeks ago are normal for age, 15-20 dBa up to about 8kHz then it’s 40-60 above that. My wife - whose voice is higher-pitched which is typical of females - says I don’t listen to her… or something.

I can’t even hear the last two keys on an 88 key piano keyboard anymore, C8 is what, 4100 Hz or thereabouts? but I CAN hear low A (A0) at 27.5 Hz but still use a subwoofer.

I’ve got a deal on a Technics ST 9038 FM tuner pending, will sell my ADCOM I did stability and audio upgrades on, I don’t listen to AM band much anyway (my Ham radio has both AM and FM); nice to know there’s someone I can rely on if I need more than I or a local tech friend can handle wrt alignment - we’re both Hams, he’s rated up to SATCOM equipment repair but it’s nice to have resources.

Is your wife a patient, or staff? Either way, I hope she gets well soon.

Nice to meet you.

- Norm

 

[Kimbrough Xu]

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/

Are there any differeces between the tuner, aux 1, aux 2 and tape 1 inputs and outputs?

 

[EJ3]

Are there any differeces between the tuner, aux 1, aux 2 and tape 1 inputs and outputs?

The tested unit here was one of my 2. I have used all of the inputs (except for the Tuner one & the phono ones) for all sorts of gear, they sound the same, so I presume that there are not any differences. Reel to Reels, Cassette decks, CD, VCR, DVD, Blu-ray, 4K equipment, all sound the same. If the input is being fed with the same signal power. If the power is higher or lower, you will have to adjust the volume. For more details, see either the owners manual (many sites have this) or this in depth revue of an unrepaired one: https://www.kenrockwell.com/audio/apt/holman-preamplifier.htm or you may text me at 1 843 789 9595.
I hope that this helps, if not, text me and I will try to answer your questions. EJ3

 

[MAB]

Are there any differeces between the tuner, aux 1, aux 2 and tape 1 inputs and outputs?

No, identical:

Tape-out has buffers, you might be able to measure a tiny difference on those. Not likely to be audible. And it is a tape-out so not many devices inserted there will suffer the added noise of the buffers!