Pioneer SX-1980 - Restoration Overview, Demonstration, & Bench Testing
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- čas přidán 9. 07. 2024
- Chapters
0:00 Introduction
0:55 Historical Context & Specs
2:27 Front Panel Review
6:15 Tuner Functions
10:26 Rear Panel Review
11:44 First Look Inside
12:20 Power Supply Maintenance
19:12 Preamp Boards
20:05 Top Covers Removed
22:18 Bench Testing - Distortion Curves
30:00 Bench Testing - Output Power
Resources:
* Orion Audio Bluebook 2001
* hifiengine.com
* Audio Magazine - September 1978 (page 70)
* www.fcc.gov/media/radio/fm-frequencies-end-odd-decimal
* toshiba.semicon-storage.com/u...
Replacement Power Supply Board:
* www.ebay.com/itm/224649092473 - Zábava
Cool info, especially on the FM tuner. I have a mint SX-1080 that I purchased in Okinawa as a Marine in 1988. Best $305 I ever spent. Listen to it daily and love, love, love it!
Another excellent video. Always interesting and informative. Thanks for continuing to make them Ben!
Excellent video and restoration, Ben!
Absolute perfection.
Problem was no one make a speaker at 8 ohm that would handle this beast. My sx1010 is all any speakers need at 100 w per channel.
I have the pioneer sx-1250. I love it. wouldn't want anything else.
A truly great video.
can you please advise me. I have always loved audio from childhood and used to get parts and put them together. Speakers were my thing. I used to go to rubbish dumps and take old speakers and connect them in crazy ways. I loved it. Now I am all grown up and realised that I lost so much joy and happiness when I stopped. I would love to know more again and start learning about audio electronics. Can you recommend a book for this.
There are not very many books out there for beginners to get started. The website AudioKarma is an excellent resource. You can also learn a great deal by watching others working on these things on CZcams. If you are interested in vacuum tube electronics search “uncle doug”. Another great teacher is “xraytonyb”
This is a lovely video and receiver shame i dont have the £11k to buy one in uk
You can replace the low value electrolytics with modern film types; they were way more expensive in the 70's. And the larger value tantalums with modern electrolytics bypassed with small ceramics ( 0805 surface mount works nice between .1" leads on the back of board ).
I haven't had a 1980; but maybe a tiny fan would be worth considering on the power supply; again, not available in the 70's.
Nice Panasonic analyzer 👍 ...is there a noise problem with the preamp/amp combination that it showed at 1 watt testing - leaky transistor or cap or carbon film resistor?
Thanks for the notes! I misspoke when talking about the tuner, the low value tantalums were my primary concern, even the 1uF electrolytics in that board tested fine. Interesting tip on the SMD bypass. For the moment so use Nichicon low leakage caps for high value tantalum replacement.
On the fan there is really not much room but it would be interesting to Mount a low noise fan and connect to the lamp supply. It’s really not necessary after these mods though.
On the distortion on the amp side it could be anything, the speaker relay is still original, switch contacts in the speaker output, multiple banana connections on the way to the dummy load… on the preamp distortion I have already replaced the failure prone transistors and all of the tants and electrolytics. Could be a resistor but more likely that it’s a slightly dirty switch contact, or aging carbon volume or balance control.
@@NovaluxStereophonic I can't think of an example in vintage audio gear where a tantalum was used for 'low leakage'. Mainly, they have lower ESR at HF frequencies; the highest voltage electrolytic that will fit the lead spacing is usually OK with bypassing. (even X7R or Z5U .01uf ceramics are OK because there is only small signal voltage variation that could change the value enough to cause measurable audio distortion)
EX: I noticed you did a video on Marantz 1122 preamp. There are tantalum's for emitter resistor bypassing in that model. 5 ohms ESR at 1 MHz makes a difference in the high frequency phase margin of those circuits. The value sets the low freq cuttoff, and a film or ceramic bypass on any electrolytic is sufficient to keep the ESR low >1MHz. Another place they might be found - power supply bypass in tuner circuits, and it's not for 'low leakage'.
A nice trick to see if leakage current is important: 9v battery with 10 meg resistor is ~1ua. That's also a method to reform the dielectric of capacitors sitting in a parts bin for years before you use them in a circuit.
Contact noise from oxidation on jacks (test equipment or device) and relays etc. could be the excess noise source. A couple years ago, a $50 gift card snuck into my wallet; sooo, I bought a bunch of gold plated RCA's and banana's for my bench... no more twisting and wiggling
@@NovaluxStereophonic On the fan: My buddy used a STA-2100D Realistic receiver as his primary power amp DJ'ing in the 80's. We put two 4" muffin fans on the top to keep it cool - worked flawlessly for years. (rebadged Pioneer SX1250)
You could double sided sticky tape a thin fan underneath 🧐
Wonderful! There was a sense of theatre about Japanese Receivers, back in the seventies. Unfortunately the Western nations took a, dare i say, dim view of hi-fi components festooned with all those knobs, buttons, lights, electro-luminescent displays, chrome, brushed aluminium and wooden casework? It's the sound, they would opine! Hi-fi, from thereon, became a medium that was only to be heard, and definitely not to be seen? Hence the plethora of lookalike black/dark brown boxes, with two knobs (three, if you were lucky) and an on/off switch! Every `unnecessary' switch, served only to rob hi-fi components of their true potential, they said? Hmmm!..can anyone truly say it made that much of a difference?
Tôi muốn mua chiếc âm ly -sx 1980 này
What did you say ?