The Sharp GF-777H Vs.The Sharp Gf-777Z!

[Johnny]

This is good to know! I am curious why the speakers stickers Fatdog has say 24 watts for the H and 90 watts for Z version was just a advertising ploy?

HUGE HUGE Advertising Ploy!

If I recall correctly, the GF-777's all use the HA1392 outputs, dual stereo modules. I believe if you do a websearch for this module, you'll find them to be about 6wpc. Dual stereo modules in non-bridged arrangement would mean 4 amps, so 24watts total would be spot on! 90watts?!? Heck, The AC input power rating is only 60watts! How you can extract 90watts out from 60watts in (and we aren't even factoring in the operational power loss yet) is beyond me but whoever can do this can probably also make cars run on water. But yeah. Deceptive Advertising exageration to the extreme. Unfortunately, also very common practice.

Thanks Super, that really cleared it up for my and also opened my eyes to the 777H's when I come across one!

 

[Ghettoboom767]

PMPO= Parially moderated pompous ouputs!!

 

[Superduper]

PMPO= Parially moderated pompous ouputs!!

Yeah, what he said.

BTW Jeff, what exactly did you just say?

 

[Ghettoboom767]

Sorry Norm-I've been typing to fast again.
PMPO=Partially Moderated Pompous Outputs!!
Like you said-advertising ploy!

 

[MasterBlaster84]

Sorry Norm-I've been typing to fast again.
PMPO=Partially Moderated Pompous Outputs!!
Like you said-advertising ploy!

Yep it's useless, let your ears do the judging.

 

[gld1307]

A few observations.

Electrical goods in general will get quite tired with all that thrashing. I would guess that many of them were played to distortion, which is bound to cause some damage. Also, there will be in significant wear and tear and depreciation of materials. These things are nearly 30 years old after all.

The fact that they are even still playing is testiment to the ingenuity and pride of the makers.

I do agree with Rimmer on the centre speakers. They do sound 'boxy' but that was approapriate for the music at the time. So much music has subharmonic frequencies now and you need real headroom to reproduce that. Sharp claim that the response os 30hz to 7khz, I think. This is simply not true at the low end. I've replaced my centre speakers and the bass is definately there.

I had one more though with the difference in sound. The 767 has less electronics in it so I would imaging that more of the power could go into reproducing the music.

I am going to take the advice of you guys and replace the crossover caps very soon.

 

[Aiwa]

z,h,he,zr

Differences:

GF-777H: 61 diodes
GF-777Z: 59 diodes

GF-777H: 24W RMS
GF-777Z: 28W RMS

GF-777H: 45W PMPO
GF-777Z: 90W PMPO

GF-777H: 12.2kg
GF-777Z: 11.8kg

GF-777H: 0.14V 22ohms (Line In)
GF-777Z: 0.2V 22ohms (Line In)

Everything else is pretty much the same, except for the radio frequencies.



(gf777:APLD
gf1000:APSS)




1981
1982
1983
1985:$248
1986
1987
The gf777, gf909, gf919, gf999, and gf1000 are all practically the same box. They have minor differences like speakers that are rated at being able to acheive lower hz or extra watts here and there. but they're not differences you're really going to notice.The gf777, gf999, and gf1000 and they all basicly sound the same. All use four 6.5" woofers so it's really not comparable to the gf9696 series.To ask if it's the "BEST" is a matter of opinion and pretty much pointless.






SPECIFICATIONS (SHARP 777Z)

GENERAL
Power source: AC 110-1 20/210-220/230-240V, 50/60Hz DC 15V (UM/SUM-1, R-20, HP-2, or "D" battery [ 10, or external DC supply)
Speakers: Super Woofer; 16cm ? 2 Woofer; 16cm ? 2 Tweeter; Horn type ? 2
Output power: PMPO 90W, with four amplifiers AC Supply operation
Semiconductors: 17-IC’s 52-Transistors 1-FET 1-SCR 59-Diodes 11-LED's
Dimensions: Width; 752mm Depth; 166mm Height; 379mm
Weight (without batteries) : 12.2kg

TAPE RECORDER/PLAYER
Tape: Philips-type compact cassette tape
Frequency response: 30Hz to 18000Hz (Metal tape) 30Hz to 1 7000HZ (Cr02 tape) 30Hz to 14000HZ (normal tape)
S/N ratio: 60dB (SNRS: ON) 56dB (SNRS: OFF)
Wow and flutter: 0.055% (WRMS)
Input sensitivity and input impedance: Ext. Mic; 600 ohms Mixing mic; 600 ohms Line in; 22 kohms
Output level and loaded impedance: Headphones; 8 ohms to 25 ohms External speaker; 4 ohms to 8 ohms Line out; 0.7V/50k ohms

RADIO
Frequency range: AM; 525kHz to 1605kHz SW1; 2.3MHz to 7.3MHz SW2; 7.3MHz to 22MHz FM; 87.6MHz to 108MHz
SPECIFICATIONS (SHARP GF-777H)

Type: stereo
Frequency range: FM 87,5-108 Mhz; SW 5,95-18 Mhz; MW 531-1620 kHz; LW 150-285 kHz
Mixing mic: Yes
Recording: ALC/manual
DIN 45511: - +0,15 %
Frequency response: Normal 30-14000Hz; CrO2 30-17000Hz; metal 30-18000HZ
APSS/APLD: APSS
Noise reduction system: SNRS
Output power: MPO 4x7 W; RMS (DIN45 324) 4x6 W
Speakers: 2x 16cmWoofer; 2x sub-woofer; 2x 5cm tweeter
Power source: DC 15 v (10 pcs batteries UM-1)
Dimensions (W)x(H)x(D): 752x379x166mm
Weight (without batteries): 12,2 kg

SPECIFICATIONS (SHARP GF-777H)
Type: stereo
Frequency range: FM 87,5-108 Mhz; SW 5,95-18 Mhz; MW 531-1620 kHz; LW 150-285 kHz
Mixing mic: Yes
Recording: ALC/manual
DIN 45511: - +0,15 %
Frequency response: Normal 30-14000Hz; CrO2 30-17000Hz; metal 30-18000HZ
APSS/APLD: APSS
Noise reduction system: SNRS
Output power: MPO 4x7 W; RMS (DIN45 324) 4x6 W
Speakers: 2x 16cmWoofer; 2x sub-woofer; 2x 5cm tweeter
Power source: DC 15 v (10 pcs batteries UM-1)
Dimensions (W)x(H)x(D): 752x379x166mm
Weight (without batteries): 12,2 kg

retro addict:

Sharp GF-777
What can I say? It's a monster! Mine's now near-mint and fully working after a good cleanup which we talked about in an earlier thread. It's amazing, I only paid £10 for this one! This is the representative of my collection and is my best box at the moment. The design is fantastic. I still can't believe how big and heavy it is!

 

[Superduper]

COOL INFO!

----------------------------------------
Got one question: In the breakdown specs for the two versions near the bottom of the post, it shows that the MPO as 4x7wpc; RMS 4x6wpc. For both models.

This suggests that both have identical power outputs, which is my observation.

Why then, the discrepencies of 24w for the H and 28w for the Z in the comparison summary above?

Not that you could hear a the difference between 24 and 28 watts. But based on the specs I'm seeing in the detail section, the difference in the numbers given in the summary comparison section is unaccounted for.

P.S. For those who don't know; the FTC RMS rating is the only comparable rating that matters. All other PMPO, Max Power, Peak Power, etc. are all advertising gimmicks. That is because manufacturers were trying all sorts of gimmicks and tricks to maximize the interpreted output power including shutting down one channel, using lab power supplies, increasing input signal strength, swapping speakers, measuring just the transient bursts.... basically anything they could do to try to eek out more power. Well, the FTC set guidelines and standards to the measurements of power and basically leveled the playing field.

 

[Ghettoboom767]

Thanks Jens!! I agree-great info.
Norm-Could the differences be in the circuitry to the speakers-It's RMS watts per channel & that's the "Real" rating!
The speakers are the same.Amps are the same-just must be the way it is wired to the speakers.Also the voltage input differences?Maybe this could be the difference between the 24 & 28.??
The power output seems the same to me at loud volumes.
I could be wrong in my assumptions but this is very informative.
Thanks Jens & Norm-These are such cool boomers.
Have a great week-GB.

 

[Superduper]

Thanks Jens!! I agree-great info.
Norm-Could the differences be in the circuitry to the speakers-It's RMS watts per channel & that's the "Real" rating!
The speakers are the same.Amps are the same-just must be the way it is wired to the speakers.Also the voltage input differences?Maybe this could be the difference between the 24 & 28.??
The power output seems the same to me at loud volumes.
I could be wrong in my assumptions but this is very informative.
Thanks Jens & Norm-These are such cool boomers.
Have a great week-GB.

Jeff. The RMS rating must be with both channels driven (if a stereo device) and the rating must include the impedance of the driven load, such as: 25wpc rms into 8ohms. You'll see it listed this way especially with audiophile receivers and amplifiers. The impedance of the driven load is important exactly because the amp's output will vary depending upon the impedance of the load. OTHERWISE, an rms rating without regards to intended loan impedance will be meaningless since an amp designed for 8 ohms will always rate lower than an amp of similar design operated with a 4, or even 2 ohm load and it would be an orange to apple comparison, exactly what the FTC was trying to stop. In the case of a boombox where the speakers are fixed and a permanent "feature" of the device, then it's not uncommon to leave out the impedance of the power but in this case, the GF-777z and GF-777h specs did not list the impedance of the loads, and we already know that the output modules are the same, and since the rating is the same (in the details section), I presume that the speakers are the same was well. The input voltage difference is a non-issue insofar as specs are concerend since the H version was introduced in Europe and wouldn't ordinarily be compared with US versions, especially since US has it's own version. In other words, the power supply is tailored to the regional AC to output (in the case of the GF-777) 15 volts output at the secondary. The outputted voltage will only change if the boombox is used outside of it's intended region with different A/C mains voltage. Only recently, with the introduction of eBay do we start to have significant importation of non-US models. It's possible that the perceived loudness of the H version vs the Z version in the US is due to feeding the H model with slightly more voltage than it was designed for, thereby artificially inflating the available voltage to the boombox. But due to the fact that decibels is non-linear but rather a logarithmic unit of measure, a doubling of the wattage would not result in a doubling of the SPL. In fact, doubling the power of an amp will only result in a 3db improvement in SPL. 1db is the smallest unit that the human ear can detect in loudness, therefore, 3db will only play slightly louder -- that is with double the power. Therefore, going back to the original argument, the difference of 24 vs 28 watts (and I don't concede that is correct) will probably result in an almost imperceivable difference in loudness. Rather, speaker sensitivity probably plays a much larger factor in perceived loudness and Jeff, since your Z and H versions employ different speakers, it's almost a certainty that the differences you are experiencing is due to speaker differences. Now as far as the tuner goes........... |-) |-) |-) oops. I feel asleep already.

 

[Ghettoboom767]

Yes Norm-I agree with what you said.I do know about speaker impediance.
I was referring to both as if they both had original stock speakers.
I'm trying to find why 1 would have 24 & the other 28.
I'm pretty sure both have the same speakers.
I also know that if you lower the resistance more power will be transmitted to the speakers.
Like my home amp-125 watts per channel at 8 ohms and 144 at 4 ohms.
But my home amp can drive lower impediance speakers.
These 777 are supposed to run 4-6 ohms I believe.
I also concur with you that the input volume doesn't neccesarilly alter the watts per channel output-at leat I don't think.?

Man you are smart about this stuff!

I used to get Car Audio & Stereo Review magazines as I'm really into audiophile stufff and I'm really into car audio!
Yeah maybe these ratings are just a little wrong but Jens' information is usually right-on & from the manufacturer!
Have a good one & I've been cranking up my Sharp GF-990G which is an amazing unit-GB.

 

[gld1307]

Well chaps,

I've replaced my crossover capacitors and all I can say is that that small change has a big effect on the output!

My gf-777 is modified, with the outer speakers being full range 2 way coaxials. I found that they were a tiny bit shy on midrange so I replaced the caps with ones rated at 22 microfarads. This give a crossover point of around 2Khz when using a 4ohm speaker, which the tweeter is.

The mids is now right up there without overpowering everything else and so the percieved loudness is much louder.

It has to be said the the original outer speakers where very efficient but I had to replace mine to preserve them as they were wearing thin around the edges.

I would dread to thing how this would sound if ALL the caps were replaced.

 

[monchito]

This is good to know! I am curious why the speakers stickers Fatdog has say 24 watts for the H and 90 watts for Z version was just a advertising ploy?

HUGE HUGE Advertising Ploy!

If I recall correctly, the GF-777's all use the HA1392 outputs, dual stereo modules. I believe if you do a websearch for this module, you'll find them to be about 6wpc. Dual stereo modules in non-bridged arrangement would mean 4 amps, so 24watts total would be spot on! 90watts?!? Heck, The AC input power rating is only 60watts! How you can extract 90watts out from 60watts in (and we aren't even factoring in the operational power loss yet) is beyond me but whoever can do this can probably also make cars run on water. But yeah. Deceptive Advertising exageration to the extreme. Unfortunately, also very common practice.

they all have the same amp circuit ha1392 as i had the 777 and i saw iras 1000 same so i do agree with norm on this one

 

[BoomBoxDeluxe]

Hi there,

If the GF-777-H has FM, MW, LW and SW, then this is the same as the GF-777-E which is what I have.

I believe that the GF-777-Z has SW1 and SW2, and no LW, right?

I have my GF-767 right here with me, and it also has the 'Z' prefix after the model number, along with the SW1 and SW2.

I wonder if the '767 was made with only one SW band, and a LW band?

Also, I believe that on most boxes, regardless of make or model, AM is the same as Medium Wave ( MW )


-BoomBoxDeluxe

 

[Superduper]

Hi there,

If the GF-777-H has FM, MW, LW and SW, then this is the same as the GF-777-E which is what I have.

I believe that the GF-777-Z has SW1 and SW2, and no LW, right?

I have my GF-767 right here with me, and it also has the 'Z' prefix after the model number, along with the SW1 and SW2.

I wonder if the '767 was made with only one SW band, and a LW band?

Also, I believe that on most boxes, regardless of make or model, AM is the same as Medium Wave ( MW )


-BoomBoxDeluxe

Well, I'm not looking at my GF-777z right now but I'm 99% certain that it does have an AM band whether it's listed as AM, MW or whatever.

 

[eldorado]

yes AM is another cmmon name for MW .

 

[Ken]

This is good to know! I am curious why the speakers stickers Fatdog has say 24 watts for the H and 90 watts for Z version was just a advertising ploy?

HUGE HUGE Advertising Ploy!

If I recall correctly, the GF-777's all use the HA1392 outputs, dual stereo modules. I believe if you do a websearch for this module, you'll find them to be about 6wpc. Dual stereo modules in non-bridged arrangement would mean 4 amps, so 24watts total would be spot on! 90watts?!? Heck, The AC input power rating is only 60watts! How you can extract 90watts out from 60watts in (and we aren't even factoring in the operational power loss yet) is beyond me but whoever can do this can probably also make cars run on water. But yeah. Deceptive Advertising exageration to the extreme. Unfortunately, also very common practice.

they all have the same amp circuit ha1392 as i had the 777 and i saw iras 1000 same so i do agree with norm on this one

This is all extremely interesting! I think, though, that the only way to determine how many watts each box is putting out is to examine the schematics for each box, if available. With Vcc (supply DC in) of 15 Volts the HA1392 will crank out 6.8 watts per channel into a 4 ohm load. But, if you pump in 12 volts, you will only get 4.3 watts per channel into the same 4 ohm load. If all these models take 10 batteries then I really doubt Sharp would go to the trouble of lowering that to 12 volts! But, I'm sure you guys have seen stranger than that, though.
For those like me with aftermarket speakers, if you want to keep blasting at 27.2 watts or whatever, you need to keep your speakers at 4 ohms. If you make the jump to 8 ohms, you'll change the load and the watts (power) will decrease accordingly.

 

[blu_fuz]

I think the previous chat about the "H" having more power is actually true, along with that the "H" captures the radio signals much clearer and easier than the "Z". I couldn't wait to test this after I read about your experiences.

The "H" is absoloutly one notch lower in volume on the knob than the "Z" and I think the "H" is still a tad bit louder...... Weird but very noticable.


No modifications to either boxes, so this is a pure 1 on 1 test.