Old Reel 2 Reel & Dolby

  • Thread starter Thread starter rayc
  • Start date Start date
rayc

rayc

retroreprobate
Hi folks,
I've recently had restored an big old stereo "Truvox of England" reel 2 reel player that has a built in modifications of VU meters etc. by "Classic Radio of Sydney". I assume it's a 60's beast. The only prob I've found to date is that there is a bump in the drive wheel at high speed that isn't there at low speed. I've been told that I'll have to locate a new rubber wheel to rectify this & they're not easily located.

I've been keen to record with it at some stage & having recorded some CDs onto a reel to test it was concerned about tape hiss.
From eBay I scored a TEAC (an AN120 or similar) Dolby encoder/decoder to deal with the perceived problem.
I haven't yet set it all up as I need extra cables & adapters etc. but shall do in the next week or so.

What I'd like to know is if there are any problems I need to anticipate with regard to using an outboard decoder. I know I can almost avoid Dolby by running a signal as hot as possible but do hope to record the odd quiet moment as well.

The thing looks almost as cool as the mono machine posted on another thread but with the big VUs & the record/playback/mixer strips down either side also looks 50's industrial.
I'd post a snap but don't have a site to host it. Is there a way around that on homerecording.com?
Cheers
rayC
 
Sounds very nice.

You can post a photo by scrolling down to the "Manage Attachments" button on a new post. Then browse to the file on your PC.

The main thing with Dolby NR is setting levels with a tone so that the signal is decoded properly. If you don't have a manual I can post a link for the AN300 (I think), which will give you the general idea.

-Tim
 
Hi Arjoll & Tim,
Thanks for the tips. the reel page is great! If I recall it's nearest match on the site was a PD80.
I'll attempt to attach 2 snaps:
1 of the machine sans it's stereo speakers
&
1 of the machine on top of the AN 180.
Thanks for the link to the manual site. I bought a copy on CDR from the US for about AU$28.oo.
I've read up on the tone generation & level setting now thanks to your prompt.
Will the Dolby take away from the essence of tape sound? I know it'll do a job on some of the hiss - how about the modulation?
Until recently I've recorded, very happily I must say, on a Yamaha MT100 4 track. I've done a fair bit of recording to tape & then recording that up to hard drive to give me the extra tracks. I'm still coming to terms with synching up multiple uploads though which means I've fallen on sad times by digitally recording all but the initial upload basic tracks. I hope to work out how Cakewalk will let me upload multiple times sooner than later.
I really like recording to tape - hence getting this little beastie up & running.
There are significant modifications from the original in comparison to the photo from the reel site. I'd assumed they were done post sale - but then again with the speakers matching the veneer & clipping on to make a BIG box for transport perhaps the mods were done in Sydney pre sale.
Thanks for the assistance folks. If there are snaps attached I've learnt something & used it just sitting here. I'll come back with a report on my success or lack thereof.
Cheers
ray
 
Still Learning

Sorry,
I had problems with the file size & by the time I'd worked it out I couldn't get ito the forum. It must have been VERY popular last night.
Here we go with snap #1.
 
Last edited:
& snap #2

Here is the machine with the TEAC Dolby unit.
 
Last edited:
Pretty cool looking...

Dolby B won’t remedy all the modulation noise, as it is most effective above 4 kHz and is primarily aimed at tape hiss. Tape selection and bias level are more important factors in controlling modulation noise.

Dolby won’t color the sound if it is calibrated properly. The notion that it cuts high frequencies is due to many consumer products with on-board NR being poorly calibrated.

However, later Dolby stand-alone products were required to include an MPX filter for FM radio, which cuts the top frequency to about 15 kHz on the Teac units. At 19 kHz (the FM pilot-tone frequency) the response is about 35 dB down.

15 kHz is pretty bright though, and most adults can’t hear frequencies much higher than that. Some units have a switch for the MPX filter, but those that don’t have that frequency limitation. I’m not sure about the AN-180. It’s probably not going to be a limiting factor for a tape deck of that age.

-Tim
 
It might not be a bad idea to look at the rest of the site I pointed you to - its homepage is http://www.ferrograph.info. Its aimed primarily at Ferrograph, but some of the info there should be useful.

I'm guessing that the company in Sydney probably bought in Truvox 'decks' (transport and heads) and added their own amplifiers - by the look of the info on the Ferrograph sites the decks were available on their own. If you look through the other pages you'll see mention of Colloro, BSR, EMI etc decks being available as well as Ferrograph/Wearite (used in Vortexion and Clarke & Smith recorders) and the Truvox stuff.

I'm not sure how much of an advantage the Dolby will be with the other limitations of equipment of this age, but its worth a try.

Finally if the Truvox has pressure pads - felt or similar pads which press the tape against the heads in record or playback mode - then you should use non-backcoated tape only on this machine. Quantegy 600 series should do the job, and 35 or 50 micron (1 or 1.5 mil) should both be ok.
 
Beck said:
15 kHz is pretty bright though, and most adults can’t hear frequencies much higher than that. Some units have a switch for the MPX filter, but those that don’t have that frequency limitation. I’m not sure about the AN-180. It’s probably not going to be a limiting factor for a tape deck of that age.

-Tim


The AN180 has the mpx filter switch. I have the same thing. Pretty cool looking unit.
 
Back
Top