Little Bear P8 Tube Preamp
I've been dabbling in Chi-fi lately because my cash flow has been very meager, but I still want to participate in our great hobby. I currently Own a Little Bear P8 headphone amp/line preamp. It has three tubes, one Chinese 6N5P, and two GE JAN 5670W tubes. This thing runs very hot, and as a tube noob, I want to know if this is normal, or if I should be concerned. The hottest parts on the amp are two gold colored caps(?) that flank the large tube. They are so hot that when I touched one of them by mistake, I got a blister on my finger. The brown caps that are next to these parts are also hot to the touch. The golden components say 20W2KJ on them.
Pic:
DSC_6856 by davidflas, on Flickr
The other hot spot on the unit is the toroidal transformer. The metal disc on top is too hot to touch comfortably. I run the pre with the acrylic top off for maximum cooling.
Pic:
DSC_6857 by davidflas, on Flickr
Here's the info provided by the Ebay seller:
P8 uses tube amplification circuit in the electronic is relatively rare in the SEPP single ended push-pull, OCL no output capacitor direct coupled power amplifier circuit. The circuit output dynamic than the cathode output generally large (undistorted swing: 30Vp-p), due to the cancellation of the output capacitance, low frequency response can dive deeper, more solid, soprano Alto can be more transparent.
But in order to make the circuit in the case of direct coupled DC level is zero, need symmetrical supply complex. In order to stabilize the operation of the circuit, and the machine also adopts a "zero servo tracking circuit". In order to ensure the safety of the output load,
Technical Parameters:
1) input terminal: a group of RCA
2), the output terminal:A:RCA output.work as preamplifier .
B. a 6.35 earphone socket.
3) frequency response: 12HZ---100KHZ (-1dB)
4) distortion: 0.05% (300 ohm, 80 mW)
The maximum output power of 5):
A. 300 mw (600/300 ohm)
A. 300 MW (600/300 Ohm)
B. 350 mw ( 120 ohm)
B. 350 MW (120 Ohm)
C. 250 mw ( 32 ohm)
C. 250 MW (32 Ohm)
6) output impedance: 32 ohm - 600 ohm
7) voltage: 110V or 220V (user specified)
8) power consumption: 80 VA
9) size: 265 (deep) X140 (W) X68 (high) mm
10) weight:1.98Kg
So, what does everybody think? Is this running hot by design? Or is it going to heat itself into an early death? I have to say that it sounds great as a preamp, I use it with my diy TPA 3116.
I've been dabbling in Chi-fi lately because my cash flow has been very meager, but I still want to participate in our great hobby. I currently Own a Little Bear P8 headphone amp/line preamp. It has three tubes, one Chinese 6N5P, and two GE JAN 5670W tubes. This thing runs very hot, and as a tube noob, I want to know if this is normal, or if I should be concerned. The hottest parts on the amp are two gold colored caps(?) that flank the large tube. They are so hot that when I touched one of them by mistake, I got a blister on my finger. The brown caps that are next to these parts are also hot to the touch. The golden components say 20W2KJ on them.
Pic:
DSC_6856 by davidflas, on FlickrThe other hot spot on the unit is the toroidal transformer. The metal disc on top is too hot to touch comfortably. I run the pre with the acrylic top off for maximum cooling.
Pic:
DSC_6857 by davidflas, on FlickrHere's the info provided by the Ebay seller:
P8 uses tube amplification circuit in the electronic is relatively rare in the SEPP single ended push-pull, OCL no output capacitor direct coupled power amplifier circuit. The circuit output dynamic than the cathode output generally large (undistorted swing: 30Vp-p), due to the cancellation of the output capacitance, low frequency response can dive deeper, more solid, soprano Alto can be more transparent.
But in order to make the circuit in the case of direct coupled DC level is zero, need symmetrical supply complex. In order to stabilize the operation of the circuit, and the machine also adopts a "zero servo tracking circuit". In order to ensure the safety of the output load,
Technical Parameters:
1) input terminal: a group of RCA
2), the output terminal:A:RCA output.work as preamplifier .
B. a 6.35 earphone socket.
3) frequency response: 12HZ---100KHZ (-1dB)
4) distortion: 0.05% (300 ohm, 80 mW)
The maximum output power of 5):
A. 300 mw (600/300 ohm)
A. 300 MW (600/300 Ohm)
B. 350 mw ( 120 ohm)
B. 350 MW (120 Ohm)
C. 250 mw ( 32 ohm)
C. 250 MW (32 Ohm)
6) output impedance: 32 ohm - 600 ohm
7) voltage: 110V or 220V (user specified)
8) power consumption: 80 VA
9) size: 265 (deep) X140 (W) X68 (high) mm
10) weight:1.98Kg
So, what does everybody think? Is this running hot by design? Or is it going to heat itself into an early death? I have to say that it sounds great as a preamp, I use it with my diy TPA 3116.
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