Gemini vIII with turn on issue,
Hello, this is my first post here, so if my etiquette is out of line please let me know.
I also am glad to see you here Stephen, just tripped across this site when researching what my chances are of resurrecting this amp. It was idle for about 10 yrs and recently (6 months) put back to use.
Unfortunately after returning to my vehicle after a short stop recently I turned on the head unit and no sound. I proceeded to verify the turn on voltage and troubleshoot. Found that the red diagnostic light was on and would only turn off if the rca input connections were removed.
I have tried reflowing the solder on the softstart circuit board hoping for a quick easy fix, but alas, no luck. Just wondering if this scenario suggests anything obvious, or what is the most logical approach for repair on the unit.
Any help from one and all would be greatly appreciated. thx
PS, will be posting this amp on ampguts as I don't see it there yet. This is for anyone else that may own or like to own this gem. (pardon the pun)
Hello, this is my first post here, so if my etiquette is out of line please let me know.
I also am glad to see you here Stephen, just tripped across this site when researching what my chances are of resurrecting this amp. It was idle for about 10 yrs and recently (6 months) put back to use.
Unfortunately after returning to my vehicle after a short stop recently I turned on the head unit and no sound. I proceeded to verify the turn on voltage and troubleshoot. Found that the red diagnostic light was on and would only turn off if the rca input connections were removed.
I have tried reflowing the solder on the softstart circuit board hoping for a quick easy fix, but alas, no luck. Just wondering if this scenario suggests anything obvious, or what is the most logical approach for repair on the unit.
Any help from one and all would be greatly appreciated. thx
PS, will be posting this amp on ampguts as I don't see it there yet. This is for anyone else that may own or like to own this gem. (pardon the pun)
thanks for the reply sdoom
Head unit appears to be ok. It has three pre-amp rca outs. Mids and sub are to the hifonics and the highs to the tweets on a separate amp.
The tweeters still work fine.
Also the power light does not come on when speaker and rca leads are all disconnected. this leads me to think initially that the turn on circuit may be the problem. Have not delved futher yet for anything other than to confirm that there are no smoked components.
Will be looking into which components on that circuit are available in the next little while.
Thx Peter
Head unit appears to be ok. It has three pre-amp rca outs. Mids and sub are to the hifonics and the highs to the tweets on a separate amp.
The tweeters still work fine.
Also the power light does not come on when speaker and rca leads are all disconnected. this leads me to think initially that the turn on circuit may be the problem. Have not delved futher yet for anything other than to confirm that there are no smoked components.
Will be looking into which components on that circuit are available in the next little while.
Thx Peter
Hey Cal, thanks
Don't worry, the reason I am the original owner of my hifonics amp is that I also am a speaker aholic, somewhat reformed over the years. But. still appreciate fidelity.
No room for the 15" subs in the house though, Wife would protest. thank goodness for well designed enclosures these days. Still have the old Hafler DH amp if I need to get some serious volume.
Pete
Don't worry, the reason I am the original owner of my hifonics amp is that I also am a speaker aholic, somewhat reformed over the years. But. still appreciate fidelity.
No room for the 15" subs in the house though, Wife would protest. thank goodness for well designed enclosures these days. Still have the old Hafler DH amp if I need to get some serious volume.
Pete
Although the hifonics amps are good in assembling quality (at least they are way better than most of the korean stuff I´ve seen) resolder all parts on the curcuit board, a lot of problems can be caused by bad solder joints, especially in older amps.
Two years ago (when I was jobless ) I fixed a lot of broken amplifiers throughout all price ranges. Over the half of the amplifiers only had bad solder joints and didn´t need spare parts.
When looking for parts, also check capacitors for leaking, if you find capacitors with a "hump" replace them, they usually are bad or at least totally out of tolerance.
when you feed power to the remote terminal (no spk or rca connected) is there a current draw ? (always use some sort of power supply with a current limiter. Hifonics amps have high effiency SMPS, the idle current even in the bigger amps is usually less than 1A , that means small power supplies can drive the amp when the amp is idling or small music levels are used.)
Steph
Two years ago (when I was jobless ) I fixed a lot of broken amplifiers throughout all price ranges. Over the half of the amplifiers only had bad solder joints and didn´t need spare parts.
When looking for parts, also check capacitors for leaking, if you find capacitors with a "hump" replace them, they usually are bad or at least totally out of tolerance.
when you feed power to the remote terminal (no spk or rca connected) is there a current draw ? (always use some sort of power supply with a current limiter. Hifonics amps have high effiency SMPS, the idle current even in the bigger amps is usually less than 1A , that means small power supplies can drive the amp when the amp is idling or small music levels are used.)
Steph
Thanks sdoom, sounds like a good place to start.
I will figure out what the basic logic on the turnon circuits is and then test the output. If that is all well I will follow your advice for a full scale solder reflow. I have done it on this board so far.
I will post the resultss for you pleasure with great Kudos if you insight is indeed the fix.
Next post with results.
Peter
I will figure out what the basic logic on the turnon circuits is and then test the output. If that is all well I will follow your advice for a full scale solder reflow. I have done it on this board so far.
I will post the resultss for you pleasure with great Kudos if you insight is indeed the fix.
Next post with results.
Peter
http://www.mouser.com/ has the mpsa12's in stock for 12 cents each. Don't know the shipping cost to overseas though.
Stephen, have you seen this?? http://www.rockfordfosgate.com/prod...id=7&family_id=24&item_id=105829&locale=en_US
Look at the weight under specs....
Look at the weight under specs....
Schematic Hifonics Colossus VIII
Hello,
I'm looking for a schematic diagram for this very nice big amp.
After it was used bridged for subwoofers, both channels and one power supply blow...I repaired the power supply (all supplys are there, other channel also).
Still there is a fault in the amps, all power transistors seem to be OK.
2x SGDS100 where defect, changed
All 2SD2155, 2SD1429 are OK..........
Please.....???
Rob.
Hello,
I'm looking for a schematic diagram for this very nice big amp.
After it was used bridged for subwoofers, both channels and one power supply blow...I repaired the power supply (all supplys are there, other channel also).
Still there is a fault in the amps, all power transistors seem to be OK.
2x SGDS100 where defect, changed
All 2SD2155, 2SD1429 are OK..........
Please.....???
Rob.
Schematics
If anyone has car audio schematics they would like to share, please e-mail them as a pdf or in a zip to chuckles951@yahoo.com. I will then post them on www.schematicsforfree.mattsoft.net if they are not marked confidential. Also, I will not publish schematics from a souce like the Sams company, where someone is trying to make a living from selling them.
But anything else, I will consider for free publication and sharing.
I can take attachments up to about 10MB. Whatever Yahoo will tolerate.
Dan
If anyone has car audio schematics they would like to share, please e-mail them as a pdf or in a zip to chuckles951@yahoo.com. I will then post them on www.schematicsforfree.mattsoft.net if they are not marked confidential. Also, I will not publish schematics from a souce like the Sams company, where someone is trying to make a living from selling them.
But anything else, I will consider for free publication and sharing.
I can take attachments up to about 10MB. Whatever Yahoo will tolerate.
Dan
Hifonics schematics
Sorry guys but all those old Hifonics amplifiers were hand drawn schematics and are no longer around besides in my head. Those were the days before computers and even when I did the first designs on computer, we never kept the schems.
Basically all the series V and on used IRFZ44 in their SMPS sections driven from a TL494. Any of these older amps we receive for repair are modified so that the IRFZ44 (IRFZ44N) are driven with proper totem pole drivers. (Hand soldered).
The amplifiers are all very close in design being full complementary designs with TIP35/36C devices (Later Gen X used the big Toshibas).
Let me know if anyone needs help.
Regards
Steve Mantz
Sorry guys but all those old Hifonics amplifiers were hand drawn schematics and are no longer around besides in my head. Those were the days before computers and even when I did the first designs on computer, we never kept the schems.
Basically all the series V and on used IRFZ44 in their SMPS sections driven from a TL494. Any of these older amps we receive for repair are modified so that the IRFZ44 (IRFZ44N) are driven with proper totem pole drivers. (Hand soldered).
The amplifiers are all very close in design being full complementary designs with TIP35/36C devices (Later Gen X used the big Toshibas).
Let me know if anyone needs help.
Regards
Steve Mantz
How lucky can we be to have the likes of Steve Mantz and Nelson Pass not just in our DIY midst, but actually willing to help.
I bow in reverence.
And thanks for all the cool stuff over the years, I hope it's been as much fun for you as it's been for me!
Tim Smith
old timey car stereo installer
Hi sir Steve Mantz it's an honor to hear from you
Hi Mr Steve Mantz and hi for all the members of this
I'm repairing a hifonics class D (1000D called "Brutus"), my problem is the next:
I have no audio signal in the output and the circuit HIP ( I dont' remember it's name right now) has overheat ( too hot) and I think with this characteristics the amplifier it's protected, I have replaced HIP circuit but doesn't work. What else can I do?....
I hope you can help me
I feel so glad you are in this forums helping us and appreciate your willing to do it.
I send to you greetings from Colima Mexico.
Hi
Hi Mr Steve Mantz and hi for all the members of this
I'm repairing a hifonics class D (1000D called "Brutus"), my problem is the next:
I have no audio signal in the output and the circuit HIP ( I dont' remember it's name right now) has overheat ( too hot) and I think with this characteristics the amplifier it's protected, I have replaced HIP circuit but doesn't work. What else can I do?....
I hope you can help me
I feel so glad you are in this forums helping us and appreciate your willing to do it.
I send to you greetings from Colima Mexico.
Hi
Hifonics and things
To all DIY'ers,
The Hifonics GEN X were the last amplifiers I designed for them and manufactured as well. Beyond that they purchased their amplifiers from Korea and China. I leave it to your imagination as to the quality of those amplifiers.
Unfortunately I have not had the pleasure of conversing with Nelson Pass, whom I have admired for many years. He is in my opinion a very smart man. The other American designer I have followed since the 70's is James Bongiorno of Dynaco, SAE, GAS and Sumo fame. Both these gentlemen I consider to be in the upper echilon of amplifier design. And please do not forget my long time friend, Tim de Paravicini of EAR fame. We spent much time together when I lived in South Africa. He is THE MAN when it comes to transformer and tape head design.
Sorry about the inability to help those with the Korean/Chinese Hifonics junk.
The HIP chips are very unreliable and were never designed for audio class D purposes but rather motor control. The HIP4080 and 4081 are the two chips to which I refer. They are always failing and shoot through with these chips is almost guaranteed.
Depending on the actual circuit used with these HIP chips, there are a few things you can do to make them more relaible. DO NOT operate them near their rated voltage - this is death for the chip.
They need back diodes on their outputs and again depending on the actual circuit design, dead time needs to be inserted. Not always possible.
Steve Mantz
To all DIY'ers,
The Hifonics GEN X were the last amplifiers I designed for them and manufactured as well. Beyond that they purchased their amplifiers from Korea and China. I leave it to your imagination as to the quality of those amplifiers.
Unfortunately I have not had the pleasure of conversing with Nelson Pass, whom I have admired for many years. He is in my opinion a very smart man. The other American designer I have followed since the 70's is James Bongiorno of Dynaco, SAE, GAS and Sumo fame. Both these gentlemen I consider to be in the upper echilon of amplifier design. And please do not forget my long time friend, Tim de Paravicini of EAR fame. We spent much time together when I lived in South Africa. He is THE MAN when it comes to transformer and tape head design.
Sorry about the inability to help those with the Korean/Chinese Hifonics junk.
The HIP chips are very unreliable and were never designed for audio class D purposes but rather motor control. The HIP4080 and 4081 are the two chips to which I refer. They are always failing and shoot through with these chips is almost guaranteed.
Depending on the actual circuit used with these HIP chips, there are a few things you can do to make them more relaible. DO NOT operate them near their rated voltage - this is death for the chip.
They need back diodes on their outputs and again depending on the actual circuit design, dead time needs to be inserted. Not always possible.
Steve Mantz
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