Akai 4000DS MK2 Reel to Reel has severe amplifier noise and very high flutter

It's NOT always capacitors. Transistors do and did fail on this one.

[@sdjgfashjasbfasd]

My wife is yelling at me now. She want's to know what that awful squalling sound is. 🤣

[@kenth8341]

Mine too

[@jmqwert]

@@kenth8341Turn down tape output, and you can hear it more clear and loud! Just close the door to the kitchen, all of the sudden the noise dissaperars..😆

[@kevinfisher1070]

Same

[@georgeprice4212]

Tell ‘em it’s a previously unreleased Yoko Ono master. (Yes, I went there….I’ll show myself out.)

[@jmqwert]

As a kid, i can recall cutting and splicing pieces of tape sections together... A really hands on technology..

[@mjg263]

Those were ok little decks. My first good reel to reel deck that worked reliably (after that nightmare Tandberg 64 I first had) was the older version of this, an Akai 4000DS [not mkII). It was all day reliable, made very decent tapes with no dropouts (unlike the Tandberg), and served me well for years. Finally graduated to the 3 motor TEAC decks and sold the little Akai.

[@alexispieltin9379]

Nice job! Had same issue and same solution... These entry level Akai were pretty decent machines, but I also share your point of view about the easy access, not to mention the protection of the boards (they don't crack when you have the naked chassis standing up...). I've salvaged one for parts in a recycling deposit. The reel to reel is like vinyle technology: it's a new trend for collectors or the next thing to have trend, but I sometimes have doubts when I see prices (on eBay), and as you also know the issue with fragile old tapes, and the mere availability of new ones. Some fools spends thousands in 15 IPS machines just to have the opportunity to access vintage studio releases, most will never acquire (keep your TEAC!)...

[@12voltvids]

My teac is just a display piece. I don't use it. For show only.

[@stevenmann9769]

@@12voltvids Or in my case a free Tascam 2 track 15ips pro deck with the remote and stand. Sounds great, direct drive too.

[@12voltvids]

@@stevenmann9769 i got a teac 3340 4 track simusync recorder which as also 15ips and 7.5. it's just for show now as I don't record on plastic and rust.

[@garp32]

Well glad you threw into this one before I did mine. Get a little peak inside beforehand. Indeed I have the same waterfall noise on all 3 of my Akai's.

[@12voltvids]

That's because akai bought cheap Japanese transistors. Oh oh, i said a word that will get all the woke people with a trans sister upset.

[@kevinfisher1070]

Sounds nice good job

[@Barbarapape]

These were very popular decks in their day but suffered a few weak spots, the cams were infamous, now parts are getting hard to find.

[@garp32]

I also have a 4000-DS Mk II. It as well as 2 other Akai decks have the noisy transistor issue. It comes and goes. I just gotta get into them and go through the amp boards.

[@johnweegenaar7314]

Nice idea of using the soldering iron to check faulty transistors

[@12voltvids]

Learned that trick over 40 years ago.

[@johnweegenaar7314]

Fire and Ice on the solid state device

[@revolvingtoto007]

I have changed all those 2sc458 transistors with Toshiba 2sc2240 In my deck's years ago, the Hitachi transistors where notorious for become noisy

[@Wurlyscope]

This is awesome because i happen to have one that make the same kind of noise. On my machine the failiure occured after i accidentally caused a feed-back loop. I guess the transistors didn’t liked it!😮

[@EastAngliaUK]

it sounds very good for tape

[@12voltvids]

DAT sounds better

[@Shadowban69]

Look at the used hifi market in Alberta. It would blow your mind. Awesome gear for high prices, but mostly serviced and restored. Edmonton is lower than Calgary and Lethbridge lower than Edmonton price wise.

[@12voltvids]

Its high everywhere because people don't know what this old stuff is really worth and get caught up in the hype. I have a bunch of stuff should sell. Could make a killing.

[@christophermurdock6327]

The Roberts 1630 has one of those sleeves but it's keyed at the back I guess to prevent slipping

[@12voltvids]

My old 1710w also has a keyed sleeve. It only comes off for 1 7/8 though as it has a 2 speed motor.

[@theotherchannel2279]

8:50 CINE FILM DAVE!!! 😘

[@12voltvids]

I know people used then for 8mm but it doesn't fit. People shoehorned film on to the wrong spool. Tape is 6.25mm and the hub spacing is 7. 8mm film went on a 9mm wide reel. It's a real pain in the ass when one comes in to be scanned because the real hugging the film causes it to jitter on my scanner. What I have to do is wind the film onto a proper reel in order to scan it.

[@rennethjarrett4580]

Another Wow and flutter or just speed and torque issue over all is due to a failing motor capacitor on the AC motor. Nice repair.... One the older or just poor quality tapes, the machine without the felts, but just use tension or a motor on the reel for tension, and nothing on the tape heads often one track will be weak or have drop outs, however to my understanding the ones without felts on the heads are the longer lasting tape heads and better machines. but with the felts you can run a tape with a soft edge and it will play decent on both channels.

[@12voltvids]

No torque issues. Aware of ac cap failure have changed it on my gx265.

[@ka7hqp182]

Very nice to see the tape take up reel with a tape pack where the tape does not touch the reel at 34:44 to 34:55 . No chance for edge damage to the tape that way. That's how it should always be done, proper tension, and no slop with a centered hub and correctly positioned. Add leader tape to your tapes and tape handling should not be an issue. Regarding the 3 3/4 speed, most reel to reels will exceed FM Radio Broadcast specifications, so 3 3/4 inches per second should not be an issue unless you use thin tapes and high recording levels to where you reach tape saturation and create distortion on your recordings.

[@12voltvids]

3 3/4 frequency response rolls off above 10khz. My teac does 7.5 and 15. Now that sounds good.

[@ka7hqp182]

@@12voltvids The Service Manual for the AKAI 4000DS MK2 states the minimum performance with regular tape to be 40 - 14,000 Hz within plus or minus 3 dB at the 3 3/4 speed, With the one-micron playback head gap that it has, it should be capable of more. Compare that with the 0.7 micron gap playback head that the Nakamichi 700 Cassette Deck has, and that it exceeds 20,000 Hz at half the speed and half the tape width. And to think, just replacing those noisy Hitachi transistors, that always fail, you upgraded not only the signal to noise, but may have improved the response as well. Unless there is excessive head wear, issues with the playback electronics, tape, or just a bad recording, that deck should "Sing like a bird" when connected to a good stereo system.

[@sdjgfashjasbfasd]

I have three of these decks and the sleeve was missing on two of them.

[@Jammerk40]

Dave is this a direct drive? Or does it have belts? Good job on fixing that machine! You like that song a lot the one you played at the end of the video!

[@12voltvids]

Belt drive capstan.

[@Jammerk40]

@@12voltvids Gotcha. Thanks

[@alex1520]

surprised it sounded as good as it did with that pinch roller on it.

[@andershammer9307]

I saw one of these for $90 at a Hamfest and bought it for $40. Turns out the track switch was smashed in and broken and the cap was missing on the pinch roller cover. I did get it working by bypassing the track switch.

[@12voltvids]

Mine was 30 and just needed switch and control cleaning.

[@CameraTimDotCom]

Since you did ask what else would you use that spool for, standard 8mm film often used them (when cheaping out from cine-specific spools)

[@12voltvids]

The hubs are a different size. Also tape is 1/4" which is 6.25 mm not 8mm as film was.

[@CameraTimDotCom]

@@12voltvids Although Super 8 used very different hubs, Standard 8 was usually compatible (at least here, in Australia, and Europe), even if the film was a very close fit into the spools (without the usual space between the 1/4" tape and spool flange). I'd done many Standard/Regular 8 dubs to video over a few decades where they came on an audio tape spool, and they fitted the Eumig projectors I had (albeit with just one locating spike to stop it spinning around, rather than three blades). The only real problem I had was that the film was now a bit further away from the projector arms than usual due to the spool width, though some projectors were built with that in mind, and if you put a thinner metal cine spool on, you had to put a spacer between the hub and the spool so the film lined up with the first sprocket. Even in radio/tv production, the audio tapes were described as either NAB spools (for the 3-inch large hubs) or cine spools (for the small spigot hub with three splines), from their cine spool origins.

[@CameraTimDotCom]

@@12voltvids If youtube lets me post a link... cameratim.com/youtube/cine-spools.jpg That's a standard 8 spool on the left, and a domestic reel-to-reel audio spool on the right. The 8mm film fits in, it's a close fit, but does slip through easily without any scraping. I was surprised they fitted, too.

[@bettinaneumeyer6760]

I am thinking that magnetic wire could be spooled up. Maybe that is why it stated for mag tape only.

[@12voltvids]

@@bettinaneumeyer6760 no it is for 8mm movie film.

[@nton1150]

nice video... just had one, and it comes with a strange "hiss/noisy/radio" parasite in every mode : source, tape, etc.. when i am in source mode, the noise is less important. it is very strange noise because it sounds like "numeric noise" (i had the same kind of sound with a pcie sound card before... isolation problem?? ) if you think about something, please let me know. thanks! :)

[@zx8401ztv]

That capstan was evil, there are good bodges and bloody horrible ones :-(. I really hated the capstan bodge. Capstans need to be clean/smooth and no wobble at all. The bronze capstan bearing needs to be perfect, no oval tendancys. I've been lucky with transistors, never had a snake in one :-D Ahh pcb connectors, a great idea but they always fail, never a big enough contact with constant pressure. Damp gets in all the time, black spots allways appear. Gold contacts should fix it but they still play up, mostly on laptop memory connectors. Sorry long waffle :-(.

[@davidgriffin79]

33:14 Initially lots of drop-outs, but then the sound improved somewhat as the recording got into the tape spool; lots of high frequency flutter though.

[@12voltvids]

All of these have flutter.

[@12voltvids]

What do you expect from a tape that is probably 60 years old.

[@davidgriffin79]

@@12voltvids I expect the drop-outs, I wouldn't expect the flutter; given the speed it was at, I'd expect it to sound better than cassette, which it didn't.

[@12voltvids]

@@davidgriffin79 these were cheap machines back in the day.

[@regenceaudio]

There used to be ‘similar’ spools for video films, I guess thats why they would say those ones were for mgnetic tapes and not something else…

[@12voltvids]

I have plenty of film reels. They are wider

[@packratswhatif.3990]

Gee dave, with the age of that machine I was wondering if those transistors were Germanium. Guess its not that old though...... at least not like I am....

[@12voltvids]

Silicon

[@video99couk]

I have a closely related Akai 1721L. They're not bad but amplifiers are a little noisy and the back tension isn't done with a reverse biased motor so it varies a little as the tape winds through. I find it best to put the very small message tapes onto a larger reel for this reason.

[@larryh8072]

I have a Sony deck that developed an intermittent noise in one channel. It was a little difficult to track down. Fortunately I have the service manual and a quick check showed the bias was way off on one of the playback transistors. Changing that solved the problem. A good quality NPN low noise audio transistor is the 2SC1815. I ordered 100 of them for just this type of repair. Great to see another deck brought back to life. m.kzbin.info/www/bejne/ppPCnnqoe9GiqpI

[@theoloutlaw]

Hello. You didn't talk much about the actual transistors you used to replace. Which type, number, whether you tested their hFe etc etc...Did you even match them at all? Cheers.

[@12voltvids]

They are just general purporse. Nte123 equivelant. I crossed the original and replacements and they both crossed to nte123. That means the voltage and gain is the same. The basing was different. Original were ECB and replacements EBC so I had to switch around leads. All perfectly acceptable. I use what i have. But going to make a special order for a couple of common BJT.

[@theoloutlaw]

@@12voltvids Ahh Ok. Thanks very much for the reply and the explanation. I always get a little 'foggy' understanding replacing transistors, and trying to match numbers, codes, and then I get all 'flustered'. Especially trying to replace vintage germanium transistors in 60's R2R decks, which is another battle in itself. Thanks Mr Volts, once again for filling in the gaps :)

[@buildanddrive]

@@12voltvids I have a working Sony TC105 reel to reel that has a bit of white noise when the deck is on but no tape is playing and on both channels. The noise increases as you turn up the volume. I tracked it down to one of the transistors using your cold spray method, it says C401w6 on it which I assume was the 2SC401, now discontinued. I can't seem to find a suitable replacement with the same voltage and gain. I found the BC63916-D74ZCT-ND but this option is the gain is only 100 @ 150mA, 2V. Do you think this will still work or do you have any other suggestions?

[@12voltvids]

@@buildanddrive My cross reference says an NTE289A is a replacement. Check the basing as some times the basing is different (EBC, BCE, ECB)

[@alex1520]

It would have been interesting to see the before and after on a W&F meter too :)

[@12voltvids]

Great send me a wf meter and i will show it to you.

[@SDsailor7]

​@@12voltvids These are not the ones with the bad ICs' right?

[@12voltvids]

@@SDsailor7 trabsistors go bad on this one. No ic.

[@alex1520]

@@12voltvids There are software ones you can get can run on your pc, just connect the device to the input of a soundcard and you're good to go. There's a well known free one called WFGUI - I've seen it used in a few videos on youtube. I cant post links obviously because youtube will eat the whole comment for doing so, but it wont take long to find online, its also mentioned on the tapehead forums.

[@12voltvids]

@@alex1520 not that I can do anything about it. I don't install any unknown software on my computer. I have one for turntable on my phone. Once you start buying new pinch rollers for hundred or more dollars it is beyond economical repair. Something like this i might make 100 on and that has to cover my time and parts. Spend 100 or more for a pinch roller on a job that I am not making much on to begin with. As i mentioned i bought one of these for 30 bucks. I see people dreaming of getting 500 or more for them on sales sites but then again i see the same units listed month after month so I they are not selling for that much.

[@garp32]

Wow.. yeah, somebody did some type of hack job on that shaft/sleeve

[@12voltvids]

Tried to make one I am sure because they run about 50 bucks to buy a proper one by the time shipping is added.

[@Musicradio77Network]

I had the Akai 1721W for years now, and it was fine, but the spindles are wobbly, and the heads are starting to wear off badly, plus some minor issues. Thankfully, I have my Panasonic RS-765US that I got off of eBay back in January and it’s a nice looking upgrade from the Akai machines. The Akai machines were notorious for problems. Panasonic and Sony were the better ones. Akai, stay away.

[@12voltvids]

Like everything akai made lol. Their amps are speaker blowers.

[@markmarkofkane8167]

Great deck! If someone recorded on a tape with that improper adapter, the tape wouldn't sound right with the proper one. Right? Oh yeah, the first one wouldn't sound right anyhow.

[@12voltvids]

It would be recorded with high flutter and played back with even more

[@charlesharkin2165]

You scratch the new pinch bearing with a metal device

[@12voltvids]

Nope no contact made.

[@b.powell3480]

Just saw where one ounce of gold is close to $2000.00 !!!

[@12voltvids]

Yes i know. I have a fair bit if gold. Whenever I have 2000 burning a hike in my pocket I buy more.

[@MrMegasuperhawk]

Luckily it's the mk-II and doesn't use those terrible Sanyo ICs

[@lucasschommer5703]

Lucas frome steven point wis u s a i hade a feling you hade something so i chek in and bame there you where thank you dave how is that data 3 part video player doing i hope you get it fix and going fore that guy thanks

[@12voltvids]

You mean the hi8 that has the bad TBC? Its a work in progress. All I can say is soon.

[@MrChrisRP]

Currently @ 18 minutes into the video when you are just starting to mess with a transistor. Even if it is not the case, I automatically think "tin whiskers" because of learning it from you. It almost seems like you quietly checked for that and didn't say.

[@12voltvids]

Nope just changed out the transistors. If it had been tin whiskers i would have mentioned it.

[@kevinharrison332]

The black deck cost a lot more money to buy

[@12voltvids]

No, people are stupid. I paid 30 for mine. People get all caught up in the vintage fad. Yes i know i could get a few hundred for it if i were to sell. Most of the high prices you see on eBay are fakes. Money launders have been using eBay to list and sell fake things to their criminal associates as a way of turning dirty money into clean money. Not as easy these days but still happens. PayPal now requires bank accounts to be linked but it wasn't always that way and there are still loop holes. People got prepaid PayPal cards and loaded them in small amounts at 711 stores. Then used these PayPal cards loaded with dirty money to buy fake vintage HiFi and other collectable stuff. The problem was the stuff they were buying didn't exist. It was a front from their own gang. The item is listed at some ridiculous price that no one in their right mind would but except the money laundering partner. Sale is complete money transferred to fake seller and fake seller ships a box with a few books inside it so the paper trail is complete. Shipping and PayPal fees are just the cost of doing business. The problem is people see the completed transactions and think that old stereo they have is worth that much and potential buyers see this too and think that's what they need to pay. Legit sellers wonder why their unit sits up for sale for weeks and never sells. Have a friend with a but Sony amp that he saw had some for 3500 and his was literally new in box. He bought it for 400 and figured he would flip it. Had it listed for months and no bites. Finally got an offer of 900 for it but is still holding out hoping to sell it for more. Last time i talked to him he had dropped the price to 2500 but still no bites, and this is for a literally new unit that had perhaps 25 hours on it before it was packed back into the original box and put on storage. That same model if you loom up has a few sales in the 3000 to 3500usd range. Guaranteed that was a laundering listing.

[@theonl1128]

Just throw it away, it's a very bad recorder.....even wen it was new. 😢

[@12voltvids]

Everything akai ever made was junk especially the glass head models.

[@blackimp4987]

recorded tape is a little dark, it lacks the highest freqs. is it the old tape or the head? it's moving watching a reel to reel repaired and in function. My father used to have a Revox A700. He sold it for the lack of room if I remember correctly. he left me some reel I'd like to listen again. some of music and I think one has voices of my families recorded. One day I 'd like to buy a good one again and listen to those reels. Could you suggest me the less critical to buy, I mean the one that had not particular flaw and it's not so hard to repair in case? thank you

[@12voltvids]

The tape is probably 60 years old. I have nothing newer than mid 60s as I don't use tape anymore for anything other than playing old media.

[@martinda7446]

Why do you do this to me? The pinch roller was shocking. It looked like it had been attacked by piranhas (''probably needs to be replaced''??) The capstan, being out of round was never gonna work, but why run a screw driver across the replacement? Why would anyone do that? Sure, very unlikely to actually do anything - except mark the surface..but still. I love your repairs, In fact your repairs have a supernatural element with your video and camera equipment..Truly remarkable knowledge and its like watching Senna doing a perfect lap at Monaco.. But I feel tense and nervous when you have a bit of quality Hi-Fi (whicha I lika to treata like a nica lady) esp. turntables. I have been left overwhelmed and bed bound for weeks after watching you shove and scrape a turntable across your bench etc... Nobody else seems to be concerned. I'm just very fussy, and have been for over 40 years of audio design and repair. For an old git, when you get a nice bit of H-iFi think of me before treating it like a prisoner in Guantanamo Bay. Nice job in the end. Leaving the spindle was a good shout, though I'd have attempted it knowing there are lots of spares for this machine. This is a tongue in cheek comment, but with a little of my criticism being genuine. Genuine, fussy old git , sure.

[@12voltvids]

The screwdriver didn't scratch the capstan sleeve. There was no pressure on it and it barely touched it. No damage done. The pinch roller is in sad shape and if the owner wants a new one it will just add to the repair cost. Changing the pinch roller probably won't change much though as it isn't slipping.

[@12voltvids]

Remember most of the turntables are mine. People give me old turntables all the time. Nobody wants them. I can't even give them away.