Almost Imperceptible Hum From Cassette Deck

MR.MAGOO

MR.MAGOO

Audioholic Field Marshall
I've got a new (1 month old) Marantz Professional model PMD 300CP cassette deck with USB. A few days ago I started hearing a faint, almost imperceptible hum when the unit is powered off. To try to isolate the problem I disconnected the RCA cable, still hums. Plugged it in different power receptacles, still hums. All this even when unit is off. I know I should take it to service center while it's still under warranty but what all of a sudden could cause this hum? Thanks for any clues!
 
TLS Guy

TLS Guy

Seriously, I have no life.
I've got a new (1 month old) Marantz Professional model PMD 300CP cassette deck with USB. A few days ago I started hearing a faint, almost imperceptible hum when the unit is powered off. To try to isolate the problem I disconnected the RCA cable, still hums. Plugged it in different power receptacles, still hums. All this even when unit is off. I know I should take it to service center while it's still under warranty but what all of a sudden could cause this hum? Thanks for any clues!
I assume that the unit is quiet if you unplug it. No one uses a simple mechanical on off switch any more. So unless unplugged the unit is actually on. The power transformer and stating circuit are always on while plugged in.

The hum is coming from a poorly potted power transformer. Since the unit only cost $149 I suspect they all do it. Since the machine has two decks and only two motors, professional grade it is not. A tape deck is complex. There are no short cuts to a good one. Providing a quality unit having two decks and a DAK at that price is impossible. Even back in the day a decent single deck professional machine cost well north of $1000.
 
Pogre

Pogre

Audioholic Slumlord
I assume that the unit is quiet if you unplug it. No one uses a simple mechanical on off switch any more. So unless unplugged the unit is actually on. The power transformer and stating circuit are always on while plugged in.

The hum is coming from a poorly potted power transformer. Since the unit only cost $149 I suspect they all do it. Since the machine has two decks and only two motors, professional grade it is not. A tape deck is complex. There are no short cuts to a good one. Providing a quality unit having two decks and a DAK at that price is impossible. Even back in the day a decent single deck professional machine cost well north of $1000.
Wow. I never realized tape decks were that expensive. Especially back in the day. Phew.
 
lovinthehd

lovinthehd

Audioholic Jedi
Wow. I never realized tape decks were that expensive. Especially back in the day. Phew.
Why I stuck it out with just a turntable back then for the most part, aside from a cassette deck for a little while, altho too many issues with cassettes, don't miss 'em. Wanted a nice reel to reel deck but content was sparse and expensive and not very portable (hardly knew anyone with one back then), and didn't really do any recording myself....

Marantz and Professional and $150 sure doesn't seem to add up....
 
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TLS Guy

TLS Guy

Seriously, I have no life.
Wow. I never realized tape decks were that expensive. Especially back in the day. Phew.
Well of course cheap single motor two head decks could be had for $100 to $200 range and up to around $500.

However you have to understand in the days of analog spending more on equipment brought a huge increase in sound quality. The digital age has changed that.

To be pro a deck had to be built with precision engineering, have three motors and three heads.

In the early seventies my three Revox machines would have been in the $700 to $800 range. These were domestic but used extensively by pros. All of those A77 were purchased as wrecks, or with a serious problem. I restored all of those personally. In addition to that, if you did not own extensive test gear, and expensive laboratory alignment tapes then you had to take the machine to the dealer at least once a year for calibration. I did my own. These trips were costly.

My semi pro Revox A 700 cost me around $1500 in the early seventies. The pro MK6 Brenell I put together from bespoke parts for around $1000. I see the Brenell prices were not published and all were price on application!

The cassette recorder was a huge problem due to very narrow tape width and very slow speed.
So to even approach Hi-Fi quality was very expensive. My three head, three motor TEAC cost me $1200 in the early eighties. Alignment was a huge problem, so the high end machines came either with auto calibration, or built in test tone oscillators and a means to set record bias and Eq with a front panel screw driver presets. The NAKS were $2000 and up.

Add to that all brands of tapes required individual calibration, even if they were of the same tape type. With the open real machines I calibrated for Ampex Grand Master and kept to it. For cassette I would recalibrate, but stick to BASF tapes as far as possible.

In the world of tape life was neither easy or cheap. Tape prices were also very high for open real. Even buying tapes in bulk pancakes, and putting together the 10 1/2 inch reels from parts running costs were over $20 per hour.

Those were the days! I started making my first live digital recordings in 1984, which was cutting edge back then. In fact I was among the first in the US to broadcast live concerts from digital recordings. At that time the BBC had a significant lead, at huge expense, which incurred the considerable ire of Margaret Thatcher. The BBC research and engineering budget has never been anywhere near as plush since.
 
Pogre

Pogre

Audioholic Slumlord
I had the cheap tape players. We didn't have a lot of money growing up. By the time I was 18 cd's had taken the world by storm. Tapes and tape decks were well on their way out.

Some of those prices you tossed out, for the early 70's, was A LOT of money. I was born in '70, but I can remember when a dollar was worth a little. Nowadays a dollar is almost like a penny. I've read some of your stuff and know you restored your tape decks yourself. You have a lot of experience and a lot of really cool gear. It seems like I learn something almost every time you post. Good times. Thanks for the history. :)
 
-Jim-

-Jim-

Audioholic General
In the olden days I had a TEAC A-6300 REEL TO REEL. I used to record all my vinyl the first time I played the Album, and then put the Album away in an Angel sleeve. (I only played the album for recording, or on special occasions for quite a while.) A TEAC A-6300 still sells for about $850 US$ on eBay!!

I have no idea what the original cost was. I do remember folks shelling $1,000 (Canadian$) for a Nakamichi 3 head cassette deck which I thought was outrageous...
 
S

sterling shoote

Audioholic Field Marshall
I still use my Sony TC-K950ES Cassette Recorder, now over 30 years old, to record tapes for playback from my 2000 Chevrolet Camaro Super Sport's factory cassette player. According to some authorities on the matter, my Sony deck was the finest Sony made, and, I believe, Sony, originally a manufacturer of consumer and professional tape recorders, may have cumulated all of their knowledge in that product. The recordings made on it and played back from it sound as good as LP. At any rate, until the advent of iTunes, I used the Sony deck to make playlists of my favorite songs, for listening pleasure at home or on the road. Now, my playlists are an iPhone thing. Times have changed, seems all is better now as far as listening to recorded music; but, my Sony is nevertheless gonna stay connected until it breaks and can no longer be repaired. I feel the same way about my Sony PCM-7010 DAT Recorders, the most magnificent electronic stereo recorders ever conceived IMHO.
24641850610_4da97510b2_z.jpg
 
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-Jim-

-Jim-

Audioholic General
I still have a TEAC V-770 Cassette Deck that's been sitting unused for ages => with a Maxell C-90 tape in it. (I loved Maxell and TDK Tapes.) It was an affordable 3 Head machine with Dual Drive motors and very decent specs. It's in a big Oak Cabinet that will be retired soon when the Misses starts renovating. I bought it to make tapes for the custom stereo system I put in my 280Z :rolleyes: before my first CD Head unit.

I hardly used the V-770 as I stopped using it shortly after I bought my first home CD Player. I had a Sony Cassette Recorder before it, which was not it this class of machine, but I mae hundreds of Tape copied of my Albums on it. The CD player was a Sony 5 Disc Carousel Model CDP-C700 (which is also in the same cabinet, and will also be retired). A Buddy and I spent $900 in November '89 and got two CDP-C700s - which was a great deal at the time. I forget what I paid for the V-770 Cassette Deck. But it was more than that.

I just saw a listing for a V-770 that was asking CAD $225.00 last December and sold. I'd be surprised if you could get $225 for this, even if it's in mint condition. (Mine have never left it's closed in cabinet.) Once in a while I'd plug it in and run the tape back and forth, through all the modes.




There is a Sony CDP-C700 listed on eBay for $50. But it has no remote control.




Actually the Sony represents the end of my Vinyl period and the start of the CD period.:p

I don't know if I can give up on my Technics SL-1700 Semi-Automatic Direct-Drive Automatic Turntable
Technics SL-1700


It was a great unit for it's time. It too resides in the bid Oak Cabinet. Ahhh... the good old days of Vinyl...o_O
 
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KEW

KEW

Audioholic Overlord
The interesting thing about he best of the cassette decks is any commercially recorded cassette sucked!
Partly because they did not take advantage of the metal tape formulations that added high frequency extension, but mainly because they could never align with another deck the way a cassette recorded on the same deck would!

PS-wonder how a tape deck became known as a deck and a turntable known as a table!
 
-Jim-

-Jim-

Audioholic General
The TEAC V-770 Cassette Deck List Price was $469 USD in 1988. That's about $600 Canadian at the time. I hear there's quite a few younger people getting into cassettes. (Which is amazing to me!)

Code:
http://www.rollingstone.com/culture/news/why-the-cassette-tape-is-still-not-dead-20160418
 
MR.MAGOO

MR.MAGOO

Audioholic Field Marshall
So for my 'professional' Marantz to be truly professional, it would need at least 4 motors since it's a double deck design? :confused:
 
-Jim-

-Jim-

Audioholic General
Mr. Magoo,

I'm of the opinion there is no such thing as a professional Cassette Deck => regardless of price. In the Audio realm, professionals used Reel to Reel Tape Decks and cassettes were left to the Consumer level.

Even my TEAC A-6300 was really a "SemiPro" deck even though it was originally purchased for a night club / disco to provide "background" music when the Bands were on break.

 
MR.MAGOO

MR.MAGOO

Audioholic Field Marshall
Mr. Magoo,

I'm of the opinion there is no such thing as a professional Cassette Deck => regardless of price. In the Audio realm, professionals used Reel to Reel Tape Decks and cassettes were left to the Consumer level.

Even my TEAC A-6300 was really a "SemiPro" deck even though it was originally purchased for a night club / disco to provide "background" music when the Bands were on break.
I kinda figured that, since my Marantz deck can be mounted in a rack (it came with brackets for that option), they decided to market it as a 'professional' deck! I mainly bought it to convert some cassettes to digital as I haven't always been successful finding what I want in that format.

Does your TEAC have remote control? The 1973 movie "Save the Tiger" with Jack Lemmon has a scene where he controls a reel to reel deck with remote control.
 
S

sterling shoote

Audioholic Field Marshall
th[5].jpg
Here's an example of professional cassette deck, A recording engineer produces a recording in the studio, the client wants a copy, and asks for it on cassette. The studio engineer makes a cassette copy of the recording on a cassette deck placed in the studio for that very purpose. So, while the deck may not have any professional qualities, its application to a professional endeavor could make the deck indeed professional. Today, its hard to believe that cassette decks are still used for the purpose described but it does happen.

BTW, I see that Sony TC-K950ES Cassette Recorders are for sale on eBay now for about $680.00.
 
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-Jim-

-Jim-

Audioholic General
Does your TEAC have remote control? The 1973 movie "Save the Tiger" with Jack Lemmon has a scene where he controls a reel to reel deck with remote control.
Sorry, no remote for that unit. I was just pleased it had solenoid controls and no levers :p:p
 
highfigh

highfigh

Seriously, I have no life.
I've got a new (1 month old) Marantz Professional model PMD 300CP cassette deck with USB. A few days ago I started hearing a faint, almost imperceptible hum when the unit is powered off. To try to isolate the problem I disconnected the RCA cable, still hums. Plugged it in different power receptacles, still hums. All this even when unit is off. I know I should take it to service center while it's still under warranty but what all of a sudden could cause this hum? Thanks for any clues!
Where is it located? If you set it on top of or adjacent to another piece of equipment, especially a receiver, it could be picking up vibrations from the power supply transformer in the other piece. Press your finger into the top and see if this hum stops- if it does, it's a physical vibration, not electrical. You can also lift it off of the shelf or cabinet and if it stops, move it.
 
3db

3db

Audioholic Slumlord
Ive picked up two Yamaha KX-800U which I picked up used for $40 and $90 respectively One came with a remote. . These decks are 3 head designs, two FF and REW speeds, HX Pro, Dolby B, C, and dbx noise reduction which new retailed for $560.US. These two machines are working flawlessly.
 
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highfigh

highfigh

Seriously, I have no life.
I just saw a listing for a V-770 that was asking CAD $225.00 last December and sold. I'd be surprised if you could get $225 for this, even if it's in mint condition. (Mine have never left it's closed in cabinet.) Once in a while I'd plug it in and run the tape back and forth, through all the modes.
Check the Completed Listings button on ebay- you might be surprised by what you see. I went to the store owned by the guy I had worked for starting in '78 and saw a turntable like mine, with a price that was $20 over the original list price. That was before MSRP, that price was full blast retail! I started looking online and saw that equipment from the '70s-'90s was selling for more than I expected, so I dusted off the old Betamax, checked it out and listed it- HOLY CRAP! I just looked it up and the thing listed for $850 in 1987! I got $275 for it a couple of years ago.
 
3db

3db

Audioholic Slumlord
A pic of the Yamaha KX-800. The upper end decks from Yamaha never achieved the recognition they deserve and can still be found used at a decent prices.

 
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