Playing With The Paramour's Output Iron
The pictures below look nasty because they are all taken at drive levels that are pushing the amplifier fairly hard.

 This page is: "6. Paramour: EXO-45-VS Output Transformer, Stock  Choke, AVVT 2A3 tubes,
Left Amp, 10% distortion curves."

This involves working with high voltages, attempt these changes at your own risk.
Many people refer to magnetics as "iron" no matter what the magnetics are made of.



Links to the pages (some with scope pictures) on this topic:

1. Paramour: Top Level Link.
             10% Distortion Tables vs Frequency. Output impedance vs Frequency.

2. Paramour: Stock Output Transformer, Stock  Choke, AVVT 2A3 M tubes,
             Right Amp, 10% distortion pictures, No distortion curves.
           This link opens a new window so you can compare it to other pages.

3. Paramour: Stock Output Transformer, EXO-04 Choke, AVVT 2A3 M tubes,
             Right Amp, 10% distortion pictures, distortion curves.

4. Paramour: Stock Output Transformer, Stock  Choke, Sino 2A3 tubes,
             Left Amp,  10% distortion pictures, distortion curves and pictures.

5. Paramour: Stock Output Transformer, Stock  Choke, AVVT 2A3 tubes,
             Left Amp,  10% distortion pictures, distortion curves.

6. Paramour: EXO-45-VS Output Transformer, Stock  Choke, AVVT 2A3 tubes,
             Left Amp,  10% distortion pictures, distortion curves,
             50Hz 100 Hz distortion curve comparison.

7. Paramour: EXO-45-VS Output Transformer, EXO-04 Choke, AVVT 2A3 tubes
             Right Amp, 10% distortion pictures, distortion curves.


Pictures of the Speaker Output Waveform from the Paramour with

EXO-45-VS Output Transformer
Stock Plate Choke
AVVT 2A3 M tubes.

Pictures taken at 10% distortion into 8.45 ohms (Left Amplifier).
An old HP 334 was used to measure the distortion.
Original IG-5282 Sine Source
Added 05/06/01 Updated 05/06/01

Not only can you see the EXO-45-VS, but you can see the AVVT 2A3M this time.

This is the left channel with the EXO-45-VS Output Transformer, stock plate choke with an AVVT 2A3 at 10 kHz, 10 usec/ div, 10% distortion. (6.4 V rms)

This is the left channel with the EXO-45-VS Output Transformer, stock plate choke with an AVVT 2A3 at 1 kHz, 100 usec/ div, 10% distortion. (6.46 V rms)

This is the left channel with the EXO-45-VS Output Transformer, stock plate choke with an AVVT 2A3 at 100 Hz, 1 msec/ div, 10% distortion. (5.79 V rms)

This is the left channel with the EXO-45-VS Output Transformer, stock plate choke with an AVVT 2A3 at 50 Hz, 2 msec/ div, 10% distortion. (4.54 V rms)

This is the left channel with the EXO-45-VS Output Transformer, stock plate choke with an AVVT 2A3 at 20 Hz, 5 msec/ div, 10% distortion. (1.77 V rms)
Notice how clean this 10% looks. It is all lower order distortion (no fast wiggles).

This is the left channel with the EXO-45-VS Output Transformer, stock plate choke with an AVVT 2A3, low level 20 Hz square wave, 5 msec/ div. No nasties are visible. The decay is clean.

Notes for Chart 4:
1. I took these distortion measurements with a Heathkit Sinewave generator that was sending 1.0 % distortion at 100 Hz and 1.5 % distortion at 50 Hz to the Paramour before the Paramour added any distortion of its own.
2. I could manually null the HP334A I was using better than the autonull would work.

Chart 4: Left Paramour with EXO-45-VS output transformer, stock plate choke:
Distortion vs Output Voltage into 8.45 ohms on 8 ohm tap with AVVT 2A3 output tube. (Left Amplifier)


New Distortion Curves
First version 05/08/01. Last change 05/08/01

I installed a new output pot in my IG-5282 sine generator so I could repeat the test voltages more exactly. I also noticed that the 9V batteries were dropping in voltage when they were loaded (the power turned on) so I put in new 9V batteries. With the new 9V batteries and new output pot, the 50 Hz and 100 Hz residual distortion dropped to 0.28%.

To make the measurements depend even more on the output iron, I used the same 12AT7 and AVVT 2A3 in both amplifiers while I was taking the measurements. The hum would adjusted down to be 4.4 to 4.6 mV in both amplifiers. The EXO-45-VS had about 6 CDs worth of burn-in for these measurements. The EXO-04 had many more hours of burn-in. Also, these measurements were taken in the same evening on a counter top instead of on the floor. All the previous tests were done with the amps on a tile floor.

At 50 Hz, I got more power out by upgrading the plate choke. At 100 Hz, I got more power out by upgrading the output transformer. The upgraded transformer had lower distortion at 100 Hz too.

A tid-bit of information: At 100 Hz, it took 0.82V input with the EXO-45-VS output transformer to get 5.00V across the 8.45 ohm load resistor on the 8 ohm output tap.



First version 05/06/01. Last change 05/06/01