Quality Quad?

[jsfiat]

The XR 4120 by Electrohome. Anyone heard of that one?
Just bought it on Ebay. here are some specs.

XR 4120 is a high performance combination tuner/preamplifier/power amplifier with four discrete channels of amplification. Nice feature is a Bridging four amplifiers into high power two channel (stereo) amplification. This receiver is capable of playing matrix-encoded programs, multiple encoded disks, and discrete tapes. Very important feature is ability of synthesis four channels from normal two channels (stereo) sources.
Not less than 150 Watts of music power for each of four channels driven simultaneously (total 600 Watts of music power)

At that time Electrohome - Planar Professional Audio Component division, was on forefront of HI-FI development.

 

[timbre4]

Having just done a search of 97 completed eBay auctions containing 'Electrohome' (with or w/o XR 4120) I cannot find the item you said you purchased there.

If it's the same company I'm thinking of they were about mid-fi in the scheme of things. (better than Panasonic perhaps but certainly not Marantz or H/K fidelity) This was the 70's afterall, there were many minor players making all kinds of claims...

Music power is one of those consumer bluffs that the FTC clamped down on and eliminated years ago. Also referred to as IPP (instantaneous peak power), it's a ridiculous number. It's merely a burst of short duration at one frequency like 1KHz. I know of no music that exists only on one frequency.

True power ratings are measured as RMS (root mean square) figures. The measurement would include all channels driven, from 20Hz-20Khz (full audible musical range) into a specified load such as 8 ohm speakers.

In summary, 150 watts of music power may actually be only about 15 watts RMS per channel. Remember that 100 watts RMS per channel only became common about 10 years after quad sound's demise. The Marantz quad receivers ranged from 10 watts to 40 watts RMS per channel in quad mode.

The amplifier strapping from 4 channels down to 2 channels was relatively common. The marketing was "buy this unit now, throw a switch when you get two more speakers".

Matrix decoding can be really cool or not very interesting. Low to mid-fi were fun but rarely as convincing as a Vari-Matrix setting on a Marantz or similar modes on Harman Kardon or Sansui models. No mention of specific matrix decoding in your message would indicate limited capabilities and/or a reluctance of the brand to license the decoding circuits to perform SQ, QS and/or RM decoding. Does it mention any of these?

 

[The Quadfather]

Hmmm... Electrohome.... Weren't they right up there with Electrophonic, Kraco, and Capehart, in terms of quality? I suspect so.

The Quadfather

 

[timbre4]

You hit the nail on the head, I just didn't want to say it.

Add Lloyd's, Morse, Airline, Bradford and Masterworks to that list....

 

[quadjoe]

Just thought you all would like to know that some Bradford gear (sold by W.T. Grant & Co.) was made by Panasonic, while most of their stuff was junk, the Bradford units made by Panasonic were identical to the brand name counterparts, they were just re-badged. Of course if you find one you have no way of knowing unless you open the case.

 

[Obbop]

Only thing regarding Electrohome I could find was their Environment 1 decoder.

THis blurb is all I ever found:

"Uses a 25 millisecond delay to enhance reverb found on stereo vinyl discs."

Using my decrepit memory, it was in an article from the quad years that very briefly informed the reader about a number of new products. The article was early in the quad years before folks generally agreed upon terminology. Heck, remember how the writers couldn't even aree upon what to term quad? Some used quadrasonic, others quadrafonic, etc etc etc.

I believe when the writer wrote "reverb" the actual term should have been one describing the inherent "hidden" "left channel minus right" natural ambience or whatever term you want. Some called it the psychoacoustic phenomena, or whatever.... Acckkkk!!!!!

Anyway..... Electrohome didn't make many items and they obviously didn't sell a lot since they so rarely appear on eBay or in the old ads, reviews, etc.

 

[QUADNUTS]

WELL, TIME FOR THE FACTS ON THIS ONE!!PLANAR WAS THE HIGHEND DIV.OF ELECTROHOME.THIS RECEIVER WAS SOLD FROM 75-77 IN CANADA.THE XR 4120 IS RATED AT 30W X4/70W X2(BTL) INTO 8 OHMS FROM 20-20,000 AT <.5 THD FROM 250MW TO RATED PWR AND THIS WAS GUARANTEED FOR 3 YEARS! IT HAS CD-4 AND FULL LOGIC SQ DECODERS BUILT IN AND USES THE SQ WITH THE LOGIC TURNED OFF FOR A SYNTHESIZER 2-4 POSITION.IT HAS NO RM/QS DECODER.THE UNITS WERE WELL BUILT WITH HUGE PWR TRANSFORMERS AND FILTER CAPS.THE SQ CIRCUITRY IS COMPOSED OF THE 3 MOTOROLA ICS' DESIGNED FOR THAT FUNCTION WITH 20DB FRONT,DIAGONALLY,SIDES,15DB FRONT TO BACK,12DB ACROSS THE BACK TYPICAL.THE CD-4 DEMODULATOR IS OF THE TWIN 16 PIN IC WITH ACL,AND 2 STAGE ANRS.THESE UNITS LOOKED AND PERFORMED LIKE MARANTZ UNITS OF THIS TIME.TO MY KNOWLEDGE THEY MADE 3 MODELS,THE XR 4120,THE XA 4120(SAME SPECS EXCEPT INTEGRATED AMP,4 VU METERS WHERE THE TUNING DIAL WAS)AND THE XR4080 A 20W RMS PER CHAN RECEIVER WITH THE SAME 4 CH. OPTIONS WITH LOWER PWR AND SAME GUARANTEE.I HOPE THIS WILL CLEAR UP ANY MISCONCEPTION OF THEIR CLAIM TO QUALITY!

 

[Solar]

I know where one is for sale in a pawn shop for$98 CDN
about $66 US. I was looking for a SQ decoder.What do you think<img src=http://www.ezboard.com/intl/aenglish/images/emoticons/ohwell.gif ALT=":\">

 

[QUADNUTS]

I THINK YOU BETTER MAKE YOUR WAY TO THAT PAWN SHOP WITH ALL SPEED!!! IF IT IS THE XR 4120 OR THE XA 4120,WHAT A DEAL!!! I HAVE HAD MY XA 4120 SINCE I BOUGHT IT NEW ON A BLOWOUT OF PLANAR EQUIPMENT FROM A HI-FI SHOP IN '77. EVEN IF THE PWR AMP IS BLOWN IN THE UNIT,AS LONG AS THE OUTPUTS HAVEN'T SHORTED,THE TURN ON RELAY SHOULD COME ON,AND YOU CAN USE THE HANDY PRE-MAIN JACKS TO FEED THE SQ DECODER/CD-4 DEMODULATOR OR FOR THAT MATTER THE WHOLE OF THE PREAMP FUNCTIONS TO WHATEVER YOU ARE USEING NOW FOR YOUR QUAD SETUP VIA THE 4 CH. AUX/4 CH TAPE PLAYBACK ON YOUR EXISTING UNIT.KEEP ME POSTED ON THE WORKING CONDITION OF THE UNIT WHEN/IF YOU GET AND I CAN PROBABLY HELP YOU OUT ON RESTORATION PROBLEMS HERE!! BEST LUCK (AND YES GO GET IT) REGARDS,BILL.

 

[Solar]

Well you should have told me to bring help getting this home. The salesman really had a good laugh when I went to pick it up. It makes my Sansui G 7000 look small.
It is heavy and it is working. Mike sounds good out of the box. There was only one bridge left I used RCA's for the other three. What else should I check out on it

 

[Solar]

What's different on the xr

 

[QUADNUTS]

OOPS...HEH,HEH, DID I FORGET TO TELL YOU THIS IS AS HEAVY AND BIG??? AT 21"WIDE,7"HIGH,19"DEEP AND WEIGHING 50# ITS' QUITE A ARMFUL ISN'T IT!! THE MAIN DIFFERENCE BETWEEN THE XA 4120(MINE) AND THE XR 4120(YOURS,U LUCKY DOG!) IS YOURS IS A RECEIVER(HAS THE TUNER) AND MINE IS THE INTEGRATED AMP(4 COOL BLUE VU METERS WHERE YOUR TUNER DIAL IS),ON YOUR SELECTOR KNOB YOU HAVE,AM/FM POSITIONS,I HAVE A TAPE ISOLATE,AND 1 MORE 4 CHAN. AUX POSITION MARKED TUNER. WHERE YOU HAVE A FM MUTE BUTTON,MINE IS A LOW FILTER. ENOUGH ABOUT THE DIFFERENCES!!!,TELL ME HOW SHE SOUNDS??ANY PROBLEMS TO REPORT??BILL:x

 

[Scottmoose]

Hi guys -something for you to try out on your amps, if you aren't doing it already. It's an old trick from the 70's that seems to have been forgotten now for some reason. Got any RCA phono inputs on the back of your amp(s) that you aren't using? If so, short them out using blanked phono plugs (make your own.) You'll tighten up the overall sound quality. Just don't try shorting tape outputs -it'll have the reverse effect. Have fun
Scott (the now obsessive tweaker of all things hifi). :

 

[Solar]

So far It's going well. A little scratchy when first turned on but after a 3 min it's fine
I dont understand what the High Blend switch does.
It's either STEREO or HI- BLEND

 

[QUADNUTS]

HI THERE,ARE YOUR ARMS BACK TO THEIR NORMAL LENGTH AFTER MOVING IT AROUND..HA..HA:lol: ? THE SWITCH GIVES YOU FULL SEPARATION IN BASS FREQUENCIES MIXING TO MONO IN THE UPPER FREQUENCIES. IT REDUCES FM OR CD-4 MULTIPLEX HISS AS WELL AS SOME PHONO NOISE,STEREO/QUAD EFFECT UNDERGOES LITTLE SUBJECTIVE LOSS. BASICALLY ITS' EFFECT IS HINGED ABOVE 15KHZ. PERSONALLY I NEVER REALLY HAVE USED IT!! THE "SCRATCHINESS THAT YOU MAY BE HEARING MAY BE FROM THE, NOT USED FOR LONG TIME, CONTROLS AND SWITCHES. THEY ALL SHOULD BE CLEANED WITH A GOOD CONTACT CLEANER LIKE "NEUTROL" OR THE LIKE. BE CAREFUL ON THE SLIDING BALANCE CONTROLS!! THE CLEANER HERE MUST HAVE A LUBRICANT IN IT,NEW NEUTROL DOES,OLD NEUTROL DOES NOT!! IF IN DOUBT USE A SMALL SPRITZ OF WD 40 IN THEM INSTEAD, DO NOT DROWN THEM!! THE NEXT THING TO LOOK AT IS THE VOLTAGE ADJUSTMENT TRIM POT ON THE PWR SUPPLY BOARD, MINE WENT BAD AND PUT A CONSTANT SPUTTERING SOUND THRU ALL SOURCES!! IT IS A STANDARD IK POT YOU CAN GET ANYWHERE,IF YOU ARE NOT TECHNICALLY INCLINDED(I.E.- DON'T KNOW WHAT YOU ARE DOING) DON'T DO IT!!! IF YOU ARE, REPLACE R408 WITH A POT TO SIZE .WITH A DIGITAL VTVM SET TO RANGE ABOVE 30VDC, SET POT HALFWAY BETWEEN STOPS, CLIP TO PIN 9 ON BOARD WITH POSITIVE LEAD,CHASSIS WITH NEGATIVE LEAD. TURN ON METER,THEN TURN ON RECEIVER. WATCH VOLTAGE CAREFULLY,SET TO 22 VDC, DO NOT LET IT FALL BELOW 15 VDC OR RAMP ABOVE 35 VDC!! HAVE YOUR TRIM TOOL IN THE SLOT BEFORE YOU TURN IT ON,AND BE READY TO TURN THE PWR OFF ON THE RECEIVER! YOU DON'T WANT FRY THOSE PRECIOUS CHIPS!!LET THE RECEIVER IDLE FOR 15 MINUTES AND RESET, IF NECESSARY AND YOUR DONE! LET ME KNOW IF THIS IS TOO MUCH INFO. HAVE YOU TRIED OUT SOME SQ OR CD-4 RECORDS THRU IT YET?? HOW' THE SOUND ??BILL

 

[Solar]

Yea the scratching sound sounds just like dirty controls but isn't. After about 3 min it goes away. The nobs do not make any noise. And the volume does not effect this sound.
After it goes the unit is sounding good. Atom heart Mother shows the logic is working well. I have a Tab DTS of AHM and it is interesting to compare. Also a classical Vaughan Williams sounded great. Mike oldfeild boxed was also good, but I wish I took better care of that set over the years. Some of the info is over my head but I will keep it if I ever need it. I found no information on this amp when searching the net.
Only in Canada you say what a pity

 

[QUADNUTS]

THATS' GREAT TO HEAR!! NOW THE "SCRATCHINESS" MAY BE SOME BAD SOLDER CONNECTIONS REARING THEIR UGLY HEAD OR SOME CAPS TRYING TO CHARGE, BUT IF THE NOISE BECOMES CONSTANT,REMEMBER THAT POT!IT WOULD BE A GOOD IDEA TO RECAP THE RECEIVER AT ITS' AGE,BUT AT THE VERY LEAST THE SQ BOARD. THESE THINGS ARE BUILT LIKE A TANK, AND THE ONLY THING I WOULD RECOMMEND WOULD BE TO START WITH A GOOD CLEANING OF THE CONTROLS AND SWITCHES. HAPPY QUADING!!

 

[Solar]

Well when I go out of the tape out I have no scratchiness. So it must be the Amp not the SQ chip.
Good thing I have two amps sitting next to it. Must need new caps?

 

[QUADNUTS]

Try pulling the pre-main jumpers and dumping the output into another one of your (quad?)amp 4 channel aux inputs. If the scratchiness goes away it is in the power amp,if it doesn't its' in the preamp. Remember,the tape outs on this receiver are like most receivers,and are before the preamp electronics,sq board,tone controls,etc.<img src=http://www.ezboard.com/intl/aenglish/images/emoticons/ohwell.gif ALT=":\">