Current Source tap on Sunfire amplifiers...

Sunfire Home Audio (Stereo) Discussions and Questions
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Carv-it-up
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Current Source tap on Sunfire amplifiers...

Post by Carv-it-up » Sat Mar 02, 2013 5:46 pm

The Current Source tap on Sunfire amplifiers have a one ohm resistor placed in series. I've heard several times that this robs wattage away from the total output of the amp. 1) Is this true? 2) If so, how much power is robbed using that tap?
I realize that the amps are extremely powerful, but curious just how much is lost.
Two Signature Cinema Grand Series II amplifiers (both are used in bi-amping my Infinity IRS Beta speakers)
Cherry 180's (use them off & on to power the mids/highs tower of IRS Beta speakers)
Sunfire Signature 600~Two amplifier (used on Thiel CS5i)
Carver TX-12 tuner
Own & working, but not in use right now - Sunfire Series II amplifier + two Carver M500t MKII amplifiers + Sunfire Classic Vacuum Tube Preamplifier preamp w/ phono & remote.

elgrau
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Re: Current Source tap on Sunfire amplifiers...

Post by elgrau » Sat Mar 02, 2013 8:08 pm

Not much.... I like my 300x2 best in the (Bob Father recommended) mode of the woofers and tweeters dual sourced. He says this gives one the best of both worlds (high current/voltage on the woofers and "tuby" sound on the tweeters). Never noticed any lack of power from using the current source...
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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Re: Current Source tap on Sunfire amplifiers...

Post by TNRabbit » Sat Mar 02, 2013 8:46 pm

You would only notice any power difference between taps unless you're running at the ragged edge of the envelope (not likely).
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Carv-it-up
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Re: Current Source tap on Sunfire amplifiers...

Post by Carv-it-up » Sun Mar 03, 2013 12:35 am

Okay. I'll go with what you guys are saying in regards to the Current Source taps and the power that is sacrificed. My Thiel CS3.6's aren't dual post speakers, so it's ALL Voltage Source or ALL Current Source for me.

This is for my bedroom system
Sunfire Tube preamp (remote & phono, but I have no turntable)
Sunfire 325 Series II power amp (thanks jjptkd)
Thiel CS3.6
Source CPU with an Audio GD NFB-2 DAC

I forgot what article(s) I saw it in, "...the power robbing current source..." They spoke as if the Boogie Man came and stole the power.
Two Signature Cinema Grand Series II amplifiers (both are used in bi-amping my Infinity IRS Beta speakers)
Cherry 180's (use them off & on to power the mids/highs tower of IRS Beta speakers)
Sunfire Signature 600~Two amplifier (used on Thiel CS5i)
Carver TX-12 tuner
Own & working, but not in use right now - Sunfire Series II amplifier + two Carver M500t MKII amplifiers + Sunfire Classic Vacuum Tube Preamplifier preamp w/ phono & remote.

angelod307
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Re: Current Source tap on Sunfire amplifiers...

Post by angelod307 » Sun Mar 03, 2013 1:32 am

Carv-it-up wrote:Okay. I'll go with what you guys are saying in regards to the Current Source taps and the power that is sacrificed. My Thiel CS3.6's aren't dual post speakers, so it's ALL Voltage Source or ALL Current Source for me.

This is for my bedroom system
Sunfire Tube preamp (remote & phono, but I have no turntable)
Sunfire 325 Series II power amp (thanks jjptkd)
Thiel CS3.6
Source CPU with an Audio GD NFB-2 DAC

I forgot what article(s) I saw it in, "...the power robbing current source..." They spoke as if the Boogie Man came and stole the power.

Ok , are you at disco grooving, light diming volumes? If not, it only affects the way it sounds. Like der rabbit said, it's only high volumes that it might be noticeable. 99% of the time for me, it is no were near that point. But that other percent i really have fun with......just kiddng. It only matters if you like it as you do have power to spare either way. What are youre thoughts using your speakers?
CarverFest: I just go for the arts and crafts

angelod307
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Location: manning, sc

Re: Current Source tap on Sunfire amplifiers...

Post by angelod307 » Sun Mar 03, 2013 1:43 am

Carv-it-up wrote:The Current Source tap on Sunfire amplifiers have a one ohm resistor placed in series. I've heard several times that this robs wattage away from the total output of the amp. 1) Is this true? 2) If so, how much power is robbed using that tap?
I realize that the amps are extremely powerful, but curious just how much is lost.
Picture this. A resistor is a flat load. So 300 x2 at 8 ohms, 600x2 at four. So at 450 that is six ohms. Then the answer i am just guessing would be a max of 75watts depending on the speakers. Keep in mind that the passive xovers as well as speakers vary in impedence as freq changes. I may have stated this wrong, but i hope the idea comes accross.
CarverFest: I just go for the arts and crafts

Carv-it-up
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Re: Current Source tap on Sunfire amplifiers...

Post by Carv-it-up » Sun Mar 03, 2013 8:12 pm

From time-to-time I like to “dim the lights” with this system, but not to often. Thanks for the information. Ima jump back and forth between the Current and the Voltage taps for now and eventually see which one sticks. I use the Current taps for my Mids/Highs & the Voltage taps for the Bass on my primary system in the living room.
Two Signature Cinema Grand Series II amplifiers (both are used in bi-amping my Infinity IRS Beta speakers)
Cherry 180's (use them off & on to power the mids/highs tower of IRS Beta speakers)
Sunfire Signature 600~Two amplifier (used on Thiel CS5i)
Carver TX-12 tuner
Own & working, but not in use right now - Sunfire Series II amplifier + two Carver M500t MKII amplifiers + Sunfire Classic Vacuum Tube Preamplifier preamp w/ phono & remote.

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