Mixers Inside: Bozak AR-4 + THD explained

First DJ mixer i want to talk about is Bozak AR-4 rotary mixer. It's a device with significant sound signature. We will see how it looks inside and also measure it.
I will also explain what is THD - Total Harmonic Distortion. Important parameter that lets us check linearity.
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[@zaffa.records]

This series of videos will be fabulous if you continue to make them with all the rotary mixers on the market! Thank you for your work!

[@mixersinside]

I will do videos with all the mixers i have access to.

[@pierredelux2319]

Yesss thanks!!

[@SpecRaceM5]

Keep up the good work! I don’t mind colored sound when done right. Engineers make compromises in mastering to make a track sound good, not only on professional grade systems, but also on the cheap headphones many consumers listen on. The only way to hear a song as the artist intended is to hear it when they record the song on the system they are hearing it on.

[@mixersinside]

Interesting point, thank you for this comment.

[@ericlloyd7981]

As the artist intended? The "artist" intended to make the kind of money that buys them a mansion in Beverly Hills and an exotic European hyper car.

[@markuseden2105]

oh... ever the "cynic".. @@ericlloyd7981

[@xavhan]

It is crazy to see the price point regarding the amount of low end components inside.

[@pauljohnson6506]

Very nice discussion here. I personally wish they would have considered tubes on this and used higher grade components. To you question-yes, mixers should have their signature sound-this helps drive market segmentation and why we have all the debate about what sound people like. I’m very fortunate to have a collection of rotary mixers each with their unique sound and I use them based on what I feel I want to hear and if I’m playing vinyl or on the 3000s. Thanks for sharing this-🙏🏽

[@satchelm0uth]

Yes, first one uploaded! Thank you for sharing the knowledge

[@zaremba8025]

interesting content here. This mixer looks very nice...outside

[@FFosaG]

This is huge! Thanks for the provided information!

[@declin_ro3823]

awesome stuff. hope you will do more mixers

[@ingmarsjansons3665]

Never had a chance to hear or try it out and nether any of other rotarys. Thanks for your enthusiasm and effort to make these kind of videos. Since I have micro understanding in electronics, they are quite informative. In my opinion most of dj mixers are way to expensive for what you get, but what's expensive for one, it's affordable for someone else. I think, if music producer have done he's/she's job well and music material is well mixed and mastered in first place than it will sound well on most decent systems. At the end of day, mixer is just one of many pieces in signal chain and where all should work well together to get pleasurable sound. Colored or clinical sound signature is preference for choice. Enjoy the music! ✌️

[@mixersinside]

WORD! Thank you for this comment. I work in hi-end audio company in R&D departament and have comparison between circuits used in DJ mixers and those used in state-of-art audio reproduction equipment. Flawless signal conditioning still requires some costly parts. Unfortunately none of them appear in most DJ mixers, and people still call those products hi-end. This channel may help to slightly get rid of this confusion (i silently hope it will). I agree in 100% that prices of DJ mixers are simply insane considering what they have to offer. And people still buy them because they are misinformed. But as you said - if someone can afford this and is happy with the purchase everything is right.

[@lewis9898]

Great video! Thanks! Personally I like super accurate mixers, I have DJd on lots of “warm” mixers, and 9/10 it leaves something to be desired or they sound good with some tracks but not all. With a very clean mixer they just play the music as it’s meant to be played

[@mixersinside]

100% agree

[@JanBajena]

Cool stuff! As a n00b in electronics I appreciate the didactive part. Keep up the good work 👌

[@ignacykorus220]

Well explained and interesting stuff, thanks!

[@satchelm0uth]

That explanation / demo of THD in Abelton was fantastic. As i dont have access to any of these mixers in country, I'm going to use that method to demonstrate / audition for myself what i might expect to hear from the mixers and use that in my purchasing decision.

[@mixersinside]

I think that this idea makes sense, but I strongly discourage buying a mixer this way! Total Harmonic Distortion (THD) is just one among several sound quality parameters. I employed THD as an indicator of the mixer's coloration, but it doesn't provide insights into aspects like transient response, intermodulation, and other intricate characteristics. I selected THD as a measurement because it tells a lot about the sound quality, but it doesn't encompass the full spectrum of factors. But sure - It's definitely worth to check if you like some amount of distortion or not before buying a mixer.

[@satchelm0uth]

@@mixersinside Noted, thank you for the guidance.

[@gunjabeans]

While this mixer may have cheap IC's here or there and high THD, it has a very pleasing sound and the layout is about as perfect as it gets.

[@pssst...]

Good video. Appreciate the well explained walkthrough

[@jacco1967]

Wonderful vids. I like how things are made and work without the marketing talk. Just how it is. I know a lot of high priced equipment have cheaply made parts inside or have odd (not the best) design decisions but that’s how it works. Anyway, keep this channel up. Thank you.

[@pjgladidiomas4180]

Great video! The "sound signature" is a very interesting topic. Personally, I'm always torn between "accurate" and a "fat/warm" sound.

[@jrey7171]

Nice work!!

[@danielhipwell3607]

Great review, thanks! Edit > are rotary mixers good for digital sources such as an audio interface like the reloop flux for example.

[@SergioRibeiro77]

Excellent video, very informative and easy to understand! (we can get an idea of ​​the average components used in this type of device) Have you tested the mastersounds two valve mk2, if so, what is your opinion?

[@mixersinside]

The point of this channel is providing content to shape your own opinion, i will provide more mixers in the future. Radius 4 mk1 is coming.

[@jonass.4449]

Amazing! Thanks for video.

[@pablomoon3470]

Really enjoying this series! Would you consider doing a video on the A&H Xone 464?

[@mixersinside]

@@pablomoon3470 i just do videos about mixers i have access to. I have Xone 62 (it's same core as 646) and i will show it in the Xone 96 video to present development of Xone series.

[@OM-hv9nb]

Another great video! Ive watched all the reviews and wanted to ask about the music. Can you list the artist and song in the description- i enjoyed them all. Cheers

[@mixersinside]

Thank you. All the info is in the description.

[@cryptout]

Separate channel boards is higher end to me. It means you can service a channel without downtime. Also yes a DJ mixer or any other analogue mixer should have it’s sound signature. If you don’t like that go mix digital ❤

[@Merstheman]

Very cool

[@QRS365]

Based on all the mixers you reviewed. Which one will you say impressed you the most?

[@SORNATcom]

Great series, big respect for the spinning table ;] Maybe this is the place for insertable or switchable tone modules? Adding such or other saturation to the TRM 303 would sell out this mixer in a few days.

[@mixersinside]

Thank you for the kind words. When speaking about TRM-303 you mean Omnitronic TRM-202 or there is another product I'm not aware of? There is of course space for the module - you must simply design such module from scratch, make it compatible and replace the original one. Shouldn't be a huge challenge.

[@havaac]

Personally i like a mixer which is transparent like a good studio console accompanied by a harmonic enhancer and/or distortion unit entirely separate from the mixer. Any "warming" on top of already warm tracks can sound quite mushy and tracks with good separation and air will lose fidelity and sonic vitality. Sadly modern Bozak is not the same as classic Bozak; for a different crowd now, i suppose. By no means is this AR-4 a poor mixer, not at all.. just not everyone's cup of tea and suited for every environment.

[@mixersinside]

So you just like to have a choice. Transparent sound with POSSIBILITY to warm things up. Reasonable approach, i also look at it this way.

[@havaac]

​@@mixersinside Absolutely, anything added (or subtracted) should be the performers' choice. Glad you also have the same view; figured from your previous videos. Your channel's fantastic by the way, love the content and how you review the gear, all of it!

[@ReasonUser]

Thanks for this videos!

[@SileDevil]

interesting nfo about THD

[@vincelin7005]

I'm wondering how the design AR-4 compares with a UREI 1620 LE, since one of the engineers involved with the LE went to product the AR-4. Do they share similar topologies and component selection?

[@JanBajena]

Nice cover image btw. Did you use a dedicated program for generating such images?

[@mixersinside]

I used an online tool called Canva.

[@dedondigital]

Interesting video! -60 dB (0,09%) is really a lot of distortion. Do you know which JFET they used in the summing amp? TL07X usage to me is really unneccessary, especially for the phono amp, as NE5532 cost about the same. But you can probably save some coupling caps on the design with the TL. And some people seem to like the sound. Is the price justified? I can't say. I mean the AR-4 is one of the cheaper 4 channel rotaries having everything you want except for effect send and return. And depending on your taste, better specifications :P Still cool they kept some of the Bozak circuit and nobody complains about the original CMA.

[@merovewallerich3105]

That's interesting, I'd like to know why a TL07x design could save capacitors, compared with a 5532-based design? if I've understood you correctly of course

[@mixersinside]

@dennidigital they used 2N5458. I also don't have strong opinion about the price, but people should definitely stop classify such mixers as hi-end devices and i'm pretty suprised that you can easily get low THD mixers for cheap and the higher THD you get the higher the price. @merovewallerich3105 TL072 is a fet input op amp which results in very low input bias current - that means you can safely DC couple the input with the phono cartridge and don't use the coupling cap.

[@merovewallerich3105]

@@mixersinside Ok I see, thanks :)

[@mixersinside]

@dennidigital and let's assume the THD of Bozak is -65dB cause -60dB was in peaking conditions.

[@dedondigital]

@@mixersinside Thanks for telling me which JFET they used. The original Bozak circuit used 2n3822. I just rewatched the video for the THD part. If I understood correctly what you did you did not measure it the way for which specs are usually given for DJ mixers which is at Unity Gain. 2V RMS Input is fine, but you should make sure there are 2V RMS on the output as well. For gain staging you usually get lowest THD when the channel volume is at maximum and house output adjusted to the 2V RMS output voltage. I wouldn't care too much about what the VU meters are saying about peaking in this case. Which soundcard are you using btw?

[@febz1982]

So Warm2 has quite better THD than Bozak and if you saturate it you can have more harmonics content?

[@mixersinside]

All the data is provided. I wouldn't say that Warm 2 has quite better THD, the difference is huge.

[@febz1982]

30dB better right? Not bad for the price difference. Thanks for your great videos!

[@mixersinside]

@@febz1982 25dB difference when hitting 0dB on the meters. Glad you enjoy the videos!

[@masterblaster8119]

A very informative channel. What dj mixer have you got personally for everyday mixing?

[@mixersinside]

UREI 1603, A&H XONE:92, Rodec MX1400 and my custom rotary are currently most used by me.

[@masterblaster8119]

@@mixersinside have you modified all of them?

[@mixersinside]

@@masterblaster8119 all apart from MX1400 but i'm also working on a mod for it. I don't like the fader curve, but it's difficult to change it in a simple way.

[@abumc5104]

​@mixersinside, excuse me, I have one question. On which rotary platform have you made your custom rotary mixer ?

[@mixersinside]

@@abumc5104 hi, can you please explain what is a rotary platform?

[@automationtraveler]

Keep in mind this company purchased the rights to the Bozak name and can’t compare to the originals.

[@arnoldvandendolder8592]

Could ypu review the inside of an ARS mixer pretty please X

[@mixersinside]

Someone must send it to me first.

[@Reticuli]

I thought the original Bozak summing amp was completely passive, basically just all the volume pots wired together.

[@mixersinside]

You can easily check it by studying the schematic which is available online.

[@Reticuli]

@@mixersinside It's not. Odd. I thought people had said it was. Maybe I misheard or they were wrong.

[@mixersinside]

@@Reticuli just do a proper search and you will find it.

[@Reticuli]

@@mixersinside By "it's not" I meant the original Bozak summing circuit is indeed not passive.

[@mixersinside]

@@Reticuli oh i see :)

[@candyproductionssouledout9682]

I have the entire system with ar6,eq6, iso x2 and meterbridge. I wouldn't do this again. The PSU are physically humming, the EQ Bands are pretty simple (not Q relativ eq slopes; this means the higher the gain the wider the bell-but they aren't like this), the VU Meter have low lights, the AR6 have a Class A topology and the EQ6 not, the Crosstalk between the Left and right channels is insanely weak .... The List goes on! I ended to build a custom psu by an electric engineer. This makes things better, but the system only work with palmer line isolators to and from the Isolator..... So, if you don't have the ability to modify forget it and buy an ARS Mixer. My mixer costs insanely 6000 Euro, for the half of the money you get a really very high end Product! Don't get me wrong i love mixing on this rig, but there are technically so many drawbacks! Believe me, i'm an acoustic engineer and know this stuff. Sorry for the bad news, but this gets me very bad.🤨😮‍💨😮‍💨😮‍💨😌

[@mixersinside]

Why do you advertise ARS? Do you have any thoughts, observations or measurements to cover your statement?

[@candyproductionssouledout9682]

@@mixersinside Hi Mixerinside, thanks for the reply! One of my clients have the Alpha Recording System Modell 9500. We are close, but not so close, that i can open his mixer😂....... But i hear it in a well treated room: The Channel Eq is on SSL Level (soundwise) and stay in a very good context with the Program Isolator. The main competitor to this mixer are the Varia Mixers (worth a try). Juno DJ have a Video here on KZbin with some EQ Examples (not the best place to critical hearing, i know). The TL072/TL074 IC's CAN work well, when the circuit is very well designed. Many Studio Consoles have these Chips in it, my Desk in the Past also (D&R from Holland/Dutch). An Audio Engineer that i know made a direct comparison with TL72/74 and OPA's (on two identical fully recapped console channelstrips; with no audible differencies (but it was measurable; lower noise floor). So, what matters is the circuit design. Have a nice Day, greetz!

[@mixersinside]

@@candyproductionssouledout9682 i've opened ARS before running this channel. It was very faithful copy of UREI 1620 with one difference - no output transformers.

[@candyproductionssouledout9682]

@@mixersinside Yes, thats right. The Japanese founder - AFAIK - Repaired Ureis and Bozaks in the Past and began building his own brand that is based on the Urei. Juno DJ confirmed that. When it is done right, it don't need Output Transformers, one Part more in the Signal Chain. But this is a VERRRRY minimalistic approach. When you take a Studio Desk, who have 'only' unbalanced inserts, it is extremely difficult to manage the wiring and grounding in Recording Studio. But it's possible! ARS have a very minimalistic approach, however, Mixing Engineers says by these things: When it feel right it is right.😎 Do you have Pictures of the inside of the ARS Mixer? That would interesting me a LOT!

[@candyproductionssouledout9682]

By the Way, nice discussion here. You have the plan here, cool BRO!

[@professorbacteriano]

Please review the Rane MP 2016s mixer

[@mixersinside]

Hello, I kindly inform that I don't do requests. If you want to see a particular mixer, please send it to me and I will film and comment it with pleasure. This channel is not financed in any way and I don't have funds to do requests. Thanks for understanding. Luckily I have Rane MP2016S already filmed.

[@ryanogorman1980]

@@mixersinsidewhere is the review? Can’t find it on your channel

[@mixersinside]

@@ryanogorman1980 i have it filmed, but it takes much longer to make the video about it. It's not uploaded yet.

[@Astroboytoy]

They said that Isonoe is the best sounding Rotary.

[@mixersinside]

Who are they? 🧐

[@Astroboytoy]

@@mixersinside There is a Video that the Isonoe creator said something to that context.

[@mixersinside]

@@Astroboytoy The creator of the device is probably not a very objective source of information. This does not change the fact that it is indeed a very good mixer, but I will never understand picking "the best" mixer. In the video that we are commenting i made a point about preferences and i consider it valid.

[@andyjohnson9714]

They should have own sound except industry standards- pioneer

[@phrayzar]

I would love to see a video on the Condesa Lucia. There is a cult following about them. I suspect a lot of the enthusiasm is based on having paid so much for them and their very nice looks. However I have used one back to back with my Omnitronic and although the sound is slightly different, I would not describe it as better, and with music with stronger mids(jazz,souletc) I preferred the omnitronic. I have yet to see a picture of the inside of the Condesa, I believe it is based on the OG Bozak.

[@mixersinside]

Yes, I also believe Condesa is based on the OG Bozak. Thank you for this comment overall, so realistic - i try to keep my channel this way. And sorry for the late answer, i didn't notice it before.

[@mixersinside]

@@mehdiel-aquil2172 why are you considering talking about someones preferences as a take to discredit Condesa? The sound of those mixers is just a matter of taste, someone may not consider it as superb and i guess we all should be fine with this. Especially when we're talking about the mixer with significant harmonic distortion that is far from transparent - not everybody likes that. I think that a decent sound engineer would answer your question "it depends". Omnitronic and Condesa represent two different sound signatures and speaking of what's better is a pure subjective thing. Speaking of technical criteria (the objective ones) we can clearly say, that Omnitronic is better in terms of distortion performance, but we all know that numbers are not everything. And again we make a circle and return to the "matter of taste".

[@mixersinside]

@@mehdiel-aquil2172 are you here for marketing purposes? I try to keep this space unbiased and talk about pure facts and you use terms like "more than a mixer". That's an educational channel that analises electrical components not social movements. I think that our discussion have quickly reached the "saturation" point and we won't come up with any fruitful conclusions. Also nobody wrote that your customers don't like the sound of your mixers. They are just likely to have their perception bent thanks to the cult and marketing that are for sure a very strong side of your company and i must congratulate you for that. You are a great salesman for sure, no offence! If you are confident enough to feature your mixer in this series feel free to contact me at [e-mail]. Cheers.

[@none9965]

@@mixersinside ​ I'm a fan of your work and appreciate your videos, but this comment is strange. OP is certainly entitled to prefer the sound of another mixer, but their comment about Condesa's customers is the one that is baseless and not rooted in science or analysis. Then you double down and say yes, in fact, Condesa's customers are influenced by marketing, and that the owner of the company commenting here is itself an attempt at marketing. I've been following rotary mixers for a few years now and don't ever recall any "marketing" that Condesa has done, aside from some interviews and posting photos of finished mixers on instagram? There are many customers who post on various rotary forums/chats/etc, simply saying they like the sound of it and are happy with it. Not sure how that's "marketing" or "cult"-like, especially when at the same time there are just as many other people who very vocally dislike Condesa mixers on those same forums all the same. I would love for them to send you a mixer to do a video on, but I also understand that's an expensive investment (it doesn't seem like any other company has sent you a mixer to review yet either). Until then it seems weird to pick fights with the folks behind these mixers that are 100% the subject matter of your channel, and it's not really fair to make an ultimatum that the discussion is over unless they send you a mixer gratis. I would love for the owners/designers/builders of all of these mixers to feel welcome to contribute to the comments here and not get talked down to. I know you were maybe trying to defend one of your viewers from some kind of attack, but this is just my opinion of how it looks from an outside perspective as your channel grows. All the best to you and keep up the good work

[@kir4us]

​ @mixersinside I own several DJ rotary mixers, including Bozak CMA, Allen V6 and some Condesa Allegra. Unlike many others, these have a very high output power, lot of headroom, so much so that with the potentiometers you rarely exceed 7 in the channels and in the master, as Larry Levan and Richard Long, pioneers of disco systems, taught. I also had a UK Bozak, the AR6 which internally was the same as the AR4 that you dismantled, but 6 channels with the eq only on the output and often it wasn't enough to turn the knobs to 10 to have enough power to drive the audio system , so it looked distortion-free, clean and faithful. I'm not a technician, but I've been working with mixers for 45 years and I've used several; the tests on Allegra done by me without electronic devices, just viewing graphics on wavelab, both with studio monitors and subsequently on power systems have shown that by pushing the volume almost to the db limit and simultaneously opening all the equalizer knobs to the maximum It had no distortion, which doesn't happen in most mixers. That said, it sounds like you've never opened a Condesa. I don't see any videos about test it. You will however know that it contains no IC and that it has transformers on the output. And the quality of the components? You saw them?....

[@braien25980]

Sold this mixer, no mojo for me, stick with my Urei 1620.

[@duczmal]

Thanks! ❤ take Pioneer A9 and V10

[@albertdesalvo7697]

I love your channel