Sunfire Stereo 300 Internal Fuses

Sunfire Home Audio (Stereo) Discussions and Questions
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electrafixion71
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Sunfire Stereo 300 Internal Fuses

Post by electrafixion71 » Sun Jul 21, 2013 7:11 pm

Hi Everyone,

It's been a couple of years since I last posted, but I"m back :D

I sold my original Sunfire 300 and Tube Preamp back in 2011, but I just picked up the identical models through a local classified ad. My new units are both in excellent cosmetic condition, and arrived with their original boxes and glass shelves. The bad news is both units need work.

Can anyone tell me exactly what fuses are supposed to be used on the amp boards internally? It seems that a previous owner has been inside this amp has replaced at least one of the original fuses after it failed. I don't want to try even powering this amp up until I know I've got the right fuses in the right places.

Thanks in advance,

Trevor
Harbeth SHL-5
Audio Research LS-27
Jasmine LP3.0 Phono
Audio Research Ref 110 / Hypex NCore NC400 based DIY amp
Audio-GD Master 7 DAC, Simaudio Mind 180 Network Renderer, Win8/i7 file server
Too many tables to count...

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jjptkd
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Re: Sunfire Stereo 300 Internal Fuses

Post by jjptkd » Sun Jul 21, 2013 7:19 pm

Bill is the go to guy for Sunfire repairs, he was Bob Carver's tech for many years and has all the OEM replacement parts and schematics from when Bob closed his repair shop.
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Oppo Sonica DAC
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electrafixion71
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Re: Sunfire Stereo 300 Internal Fuses

Post by electrafixion71 » Mon Jul 22, 2013 8:35 am

Thanks jjptkd,

I'm sure Bill's the guy to sort these units out, the shipping cost alone from Canada makes that prohibitive.

Surely someone must know what the correct values are for the internal fuses.

Trevor
Last edited by electrafixion71 on Mon Jul 22, 2013 7:55 pm, edited 1 time in total.
Harbeth SHL-5
Audio Research LS-27
Jasmine LP3.0 Phono
Audio Research Ref 110 / Hypex NCore NC400 based DIY amp
Audio-GD Master 7 DAC, Simaudio Mind 180 Network Renderer, Win8/i7 file server
Too many tables to count...

angelod307
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Re: Sunfire Stereo 300 Internal Fuses

Post by angelod307 » Mon Jul 22, 2013 11:06 am

Only if someone takes their amp apart to check what is in it. Nothing technical is published on the amps. Only bill and bob have schematics .
CarverFest: I just go for the arts and crafts

elgrau
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Re: Sunfire Stereo 300 Internal Fuses

Post by elgrau » Mon Jul 22, 2013 12:19 pm

Hi Trevor,
Never had the hood up on my 300x2 but this might be an excuse to do so. Perhaps tonight I can do this and IF the fuses are easy to remove and IF they have values on them I'll try and get these to you....Real Soon Now... :lol: - Ed
FR: 400 disk changer with PS Audio Digital Link III DAC; Technics SL-1100A TT. QED Quenx1 IC's from DAC & TT to Adcom GTP-602 preamp/Tuner. AudioQuest King Cobra IC's from preamp to M1.0t mk-II opt2. QED Silver Spirals 4M wires to EPI 1000’s.
LR: AudioEngine wireless link from family room preamp to Barcus-Berry 2002R Sonic Maximizer to GlowPower Zyxt IC's to Sunfire 300x2 to Nordost 6M bi-source wires to AOS 28" MDF spherical speakers using six 6.5" woofers and eight 1" dome tweeters symm. arranged around the surface.
SS system: CX-995V DVD to AV-634x 3-4 channel amp (center/rears) & M1.0t mk-II opt2(fronts).
Garage: 300 disk changer to Entech 202.5 DAC to MXR150 Receiver (pre) to TFM-42 to EPI 400 speakers.

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electrafixion71
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Re: Sunfire Stereo 300 Internal Fuses

Post by electrafixion71 » Mon Jul 22, 2013 7:35 pm

Thanks Ed! If you're really dying to see the inside of your 300 it would be great to find out what you see, but I THINK I have it figured out. My new Stereo 300 has 20A fuses in every internal position except one, which has a 10A slow blow fuse. I found some old photos of my first Stereo 300 on my computer earlier today, which I took when I was upgrading the binding posts. I could clearly see that none of the fuses in my original 300 were the slow blow type, so I'm going to guess that 10A is the one the previous owner installed. Just by luck I found a couple of 20A standard fuses in my garage, so I think I'll install one, hook up some speakers I don't care about, and fire the amp up. If the fuse blows, or the speakers, I'll probably call Bill and make arrangements for a servicing.

Wish me luck!
Harbeth SHL-5
Audio Research LS-27
Jasmine LP3.0 Phono
Audio Research Ref 110 / Hypex NCore NC400 based DIY amp
Audio-GD Master 7 DAC, Simaudio Mind 180 Network Renderer, Win8/i7 file server
Too many tables to count...

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jjptkd
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Re: Sunfire Stereo 300 Internal Fuses

Post by jjptkd » Mon Jul 22, 2013 8:20 pm

20 amp? :-k Seems a bit high to me considering the main power fuse is only 12 or 15 amp. I don't know though but its better to be safe then sorry.
Oppo Sonica DAC
Sunfire TG-III
Sunfire 300x2
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angelod307
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Re: Sunfire Stereo 300 Internal Fuses

Post by angelod307 » Mon Jul 22, 2013 10:52 pm

20 amp equal smoke. I could be wrong.
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elgrau
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Re: Sunfire Stereo 300 Internal Fuses

Post by elgrau » Tue Jul 23, 2013 12:29 pm

Ok; will hold off for now since it's a bit of work to un-hook everything and hoist it off it's shelf and remove the cover, etc.... Let me know. - Ed
FR: 400 disk changer with PS Audio Digital Link III DAC; Technics SL-1100A TT. QED Quenx1 IC's from DAC & TT to Adcom GTP-602 preamp/Tuner. AudioQuest King Cobra IC's from preamp to M1.0t mk-II opt2. QED Silver Spirals 4M wires to EPI 1000’s.
LR: AudioEngine wireless link from family room preamp to Barcus-Berry 2002R Sonic Maximizer to GlowPower Zyxt IC's to Sunfire 300x2 to Nordost 6M bi-source wires to AOS 28" MDF spherical speakers using six 6.5" woofers and eight 1" dome tweeters symm. arranged around the surface.
SS system: CX-995V DVD to AV-634x 3-4 channel amp (center/rears) & M1.0t mk-II opt2(fronts).
Garage: 300 disk changer to Entech 202.5 DAC to MXR150 Receiver (pre) to TFM-42 to EPI 400 speakers.

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electrafixion71
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Re: Sunfire Stereo 300 Internal Fuses

Post by electrafixion71 » Tue Jul 23, 2013 2:05 pm

Thanks Ed! I don't think I'll need you to check, as I'm now certain about the 20A value:
- 5 out 6 locations on this amp has them in place
- I can see the physical size of the filament in the photos of my old Stereo 300, and they are larger than the 10A and 15A which I have on hand

With respect to the comments on 20A being too high since it only takes a 10A on the power line, remember that V x A = W. The amp can pull 1200 watts (120V x 10A) from the wall. The power supply converts the 120V much lower voltage with much higher amperage internally, so 20A isn't unreasonable.

Most importantly: I've now powered the unit up, and it seems to be working fine so far. \:D/ \:D/ \:D/

The Minimus 7 speakers I have connected to it have never sounded so good!
Harbeth SHL-5
Audio Research LS-27
Jasmine LP3.0 Phono
Audio Research Ref 110 / Hypex NCore NC400 based DIY amp
Audio-GD Master 7 DAC, Simaudio Mind 180 Network Renderer, Win8/i7 file server
Too many tables to count...

User avatar
electrafixion71
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Posts: 84
Joined: Thu Sep 10, 2009 4:36 pm
Location: The Independent Republic of Alberta

Re: Sunfire Stereo 300 Internal Fuses

Post by electrafixion71 » Tue Jul 23, 2013 7:30 pm

A further update...

About an hour ago I installed a blue LED in place of the burnt out meter bulb, thanks to TNRabbit's excellent post.

Now I have the new to me Sunfire 300 powering my NHT 3.3's at very high volumes with no signs of distress. And the joules meter is softly glowing blue :)

I'm kind of thinking the previous owner's problems might have simply been the use of a 10A fuse where a 20A was required.

Next thread...why is there only one channel working in my preamp? Perhaps it caused the original fuse failure in the amplifier.
Harbeth SHL-5
Audio Research LS-27
Jasmine LP3.0 Phono
Audio Research Ref 110 / Hypex NCore NC400 based DIY amp
Audio-GD Master 7 DAC, Simaudio Mind 180 Network Renderer, Win8/i7 file server
Too many tables to count...

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