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- Users: Bolder
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REVIEW: the Bolder-Rebuilt Singlepower Extreme
Here is an early picture of the internals of minimus' rebuilt Extreme. Some of the wiring had to be shortened and rerouted. Bypass caps were added to the output coupling caps. The signal wiring was changed a bit. This should give you an idea of what had to be done to...- Bolder
- Post #8
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Quote: -The transformers on all stock Extremes or all SinglePower Extremes appear to require replacement. This is not horribly expensive ($175-$300, installed depending on the transformer and hourly labor cost). The first part of this statement is absolutely true. The transformers on...- Bolder
- Post #321
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Here is a nice, fuzzy shot of a completely rebuilt Extreme. This unit was pretty much stripped to the chassis. The RCA input connectors, AC inlet, AC switch, volume control, LED and headphone connector are just about the only things left from the stock unit. The transformer was...- Bolder
- Post #308
- Forum: Headphone Amps (full-size)
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My Singlepower Supra Experience - Why mine almost blew up like a Hand Grenade (and yours might too)
The 120 volt versions usually used Hammond transformers. There is a 120/240 series of Hammond transformers, that is probably what was used. What matters is what the filament current spec is. A fairly easy way to determine if your transformer is undersized is to measure the filament voltage...- Bolder
- Post #308
- Forum: Headphone Amps (full-size)
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My Singlepower Supra Experience - Why mine almost blew up like a Hand Grenade (and yours might too)
Use as high current a diode as you can fit. The biggest problem will be to get rid of the heat generated by the current passing through the diodes. Something like a large bridge rectifier bolted to the back of the chassis may work best to radiate away the heat. This will not help if the...- Bolder
- Post #304
- Forum: Headphone Amps (full-size)
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My Singlepower Supra Experience - Why mine almost blew up like a Hand Grenade (and yours might too)
Quote: Originally Posted by fongalv I understand the issues of the need for the bleeder resistors across the caps and the underspeced voltage switch(which would be more tricky to mod), but since I'm not touching the large caps all the time, and neither am I fiddling with the voltage...- Bolder
- Post #302
- Forum: Headphone Amps (full-size)
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My Singlepower Supra Experience - Why mine almost blew up like a Hand Grenade (and yours might too)
I just finished looking at a MPX3. This one has the high/low voltage switch that is rated at 25 volts. No balancing resistors. Black Gates on the HV section. A couple of Russian Teflon caps and this: An under $30.00 power transformer. This amp was running a pair of 6BL7GTAs for outputs...- Bolder
- Post #295
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Here are some shots of the latest Extreme to visit me. First is the standard overheated transformer. In this amp's case, it led to failure of the capacitor in the filament circuit. In other words, the cap puked it guts out. Here is the bottom of the case with more cap puke...- Bolder
- Post #306
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Your amp is in fairly poor shape with all the overheated parts. The high voltage circuit should be removed. It does not improve the sound when running the output tubes at high voltage. If anything, it degrades the performance. The switch is rated 25 volts. It is likely to fail at any time...- Bolder
- Post #303
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Sorry to be the bearer of bad news, but the Plitron transformers used in the Singlepower Extreme Platinum are wired up the same way as the Hammond transformers discussed in the first post in this thread. The dual primary taps, which are supposed to be run in parallel for 120 V and series for...- Bolder
- Post #279
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Here are some photos of a Platinum Extreme sent to me. This one was built on a MPX board. The light blue cap in the middle is the smoothing cap for the filament supply. Does it look like it may have been under some stress? BTW, filament voltage was measured at 4.0. Other side...- Bolder
- Post #262
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Thank for your comments, Skylab. I just spoke to the owner of the Extreme after he saw the photos. He actually likes the look. Kinda like the Donald North amps with their bright blue chassis. Beauty is in the eye of the beholder The bridge rectifier for the filaments is bolted the the...- Bolder
- Post #199
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Here is the Edcor transformer mounted on a small chassis Extreme Same amp with transformer cover placed over the Edcor. This amp also had the HV diodes replaced and film caps added to the output caps.- Bolder
- Post #197
- Forum: Headphone Amps (full-size)
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My Singlepower Supra Experience - Why mine almost blew up like a Hand Grenade (and yours might too)
PhilS Supra has been repaired/updated/made safe. Here is his picture of the unit. 100K 2 watt resistors were placed across the juice can caps. The rectifier diodes for both high voltage and filaments were replaced with HexFREDs. The transformer wiring through the chassis had additional...- Bolder
- Post #276
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Nice job, Miguel. The diodes directly under the power switch look like they have been getting warm. The circuit board is discolored under them. I suggest you may want to check their rating and maybe replace them with higher current and voltage HexFREDs. Two 6BL7 want 3 amps. Add in the...- Bolder
- Post #144
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
I received the Edcor transformer today. The bells ARE very blue. Here is a shot of it next to the transformer it is going to replace. Here is another picture of it turned 90 degrees. This particular Extreme is a circuit board model with the "upgraded" 12 amp transformer. The...- Bolder
- Post #143
- Forum: Headphone Amps (full-size)
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How big is your FLAC library?
Total tracks: 40,939 Total Albums: 4,014 Spread across 2) 250 gig hard drives and 2) 330 gig drives. Backed up on 5) 250 gig external drives. Most of my ripping was done a couple of years ago. The best value per dollar was the 250-330 gig range. Now it is looking like 1-1.25 terabyte for...- Bolder
- Post #24
- Forum: Dedicated Source Components
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My Singlepower Supra Experience - Why mine almost blew up like a Hand Grenade (and yours might too)
Actually you should be fairly safe with the 6BL7/6BX7 as output tubes. They draw 1.5 amps each. It you use a 6SN7 as a driver, you would be pulling roughly 3.6 amps. The 6AS7 draws 2.5 amps each. Using those tubes would possibly be a problem. I would suggest that you consider completely...- Bolder
- Post #240
- Forum: Headphone Amps (full-size)
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My Singlepower Supra Experience - Why mine almost blew up like a Hand Grenade (and yours might too)
Frihed89, I will make a guess that the transformer in your unit is a Hammond 378X. Hammond 300 series This is the universal voltage version of the 278X used in Tyson's Supra. There are many taps on the primary side to allow it to run anywhere from 100V to 240V. It also has an...- Bolder
- Post #237
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Thank you, Nate. It is Wayne. I have just been notified that the EDCOR transformer I ordered two weeks ago has shipped. It should arrive on Friday. I'll take some pictures of it to post here so everyone can make up their own mind as to how it looks compared to the "stock" transformer. I...- Bolder
- Post #139
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Paul, I have sent E-mails to Jude, but I have yet to hear back from him. I will not post again here until I am contacted. Sorry if I violated any of the rules. I was only trying to help.- Bolder
- Post #129
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Another alternative might be to use a transformer cover. If you have the room, these might work for you. At least they are reasonably priced.- Bolder
- Post #118
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
My apologies for the misinformation. I did order transformers from them before and they did offer gray bells. I have heard of others removing the bells and painting them with epoxy based paint.- Bolder
- Post #116
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Quote: Originally Posted by nurxhunter The tech pro I gave the amp to at closing managed to look at it in the evening. Not much detail, his response is below. If someone can recommend an alternate to the Edcor that would be appreciated. I am partial to black over blue, unless the...- Bolder
- Post #114
- Forum: Headphone Amps (full-size)
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Warning About The Singlepower Extreme - Owners Please Read
Quote: Originally Posted by nurxhunter Thanks, Kevin--nice of you to help the weak. If one of ordinary skill in field can easily replace transformer--and wire it properly (can any tech do this--do you think based on pictures on the site?), which of the two transformer would you...- Bolder
- Post #70
- Forum: Headphone Amps (full-size)