Gemini DJ PA-7000

This is a usable analog preamplifier HiFi (after a few improvements).

UTILIZATION

Simple manual, obvious connections

SOUND QUALITY

No staining but various noises (bad bad power transformer and filtered)

It can be improved very easily, in which case it becomes great:
- Change the voltage by an impregnated model (planar transformer primary side 2 x 115 V 2 x 18 V 18 VA Spitznagel SPF SPF 1,831,818 1,831,818).
mount the transformer on small foam pads
- Change the filter capacitors by 600 μf/50v.
- Replace the original op amps by NE5532P (4)
- Thoroughly check all welds of the device (it's made in China).

total cost of changes: 25 euros with shipping!
The sound becomes perfect: more noise, more breath and RIAA entry worthy of the name

OVERALL OPINION

very good buy if small modifications, simple but thorough is performed
The next step in customization will be the replacement of all chemicals and other knobs and switches capacitors,

I use to pre-amp for 2 years he can use my sound system as string Hi-Fi easily.
It possde input anx 4, cd, tuner, phono, input / output for a recorder or other platinum K7, there is also a microphone input mixable. SETTING THE The volume is large but not too prcis beyond mid power.

Sensitivity of impedance between
1mV micro 3Kohm thd 0.02% S / N 70dB
phono 3mV 47kohm thd 0.04% S / N 90dB
machine 150mV 22Kohm 0.01% THD S / N 100dB

Output:
Registration 150mV 3Kohm
pr-11V output 1Kohm

gnralite:
5Hz-30kHz response frequnce +0,-3dB
Bass + /-12dB 100Hz
med + /-9dB 1KHz
AIGS + /-12dB 10KHz
lourdness 9 / 0 / +9 dB 100/1K/10K
-20dB mute

PSU 120/230V 50/60Hz 15W

UTILIZATION

Full record
used as a hi-fi amp btte
between mic for karaoke

SOUND QUALITY

The 3-band equalizer is handled with dousseur because it is a little too straight forward as I got lonrdenss function. The function is handy kut low for vinyl. The amp RIAA is correct and does not stain like the pre-amp gnral.

OVERALL OPINION

Ngatif points:
_ Tranfo vibrates and makes some noise
_ Equalizer lourdenss tops and nag
_manque one or two supplmentaires input (TV, VCR ...)
Positives:
_ Unique product in this price range
_ 2 RCA 1 XLR
_ Trs quality sound right no breath and no audible distortion