A-08S WE101 D/WE104D version Ordering start

At our company, many persons observe the amplifier which adopted WE205D of the Western Electric as the year before last including sale as a sister machine of A-08S, and quantity was, and I received evaluation.

WE205D is known by many persons also in the vacuum tube of a Western Electric also as a vacuum tube not only with the form but a sufficient sound.

It does not change as comment which manufacture amplifier at our company.

However, although output power is smaller, WE101D, WE104D, and the opinion that sound is as good as it are heard well.

Although those opinions were worried as our company, it was apprehensive with whether sound pressure for actual use with output power anyway sufficient in the size which is less than 1W is obtained, and had not experimented until now.

Since the vacuum tube of those samples was recently obtained, the experimental model was manufactured.

As a result, since it turned out that the sound quality of the expected more than is obtained, and the output power is also fully equal to practical use, I decided to commercialize formally.

By the data of WE, when operating WE101D with rated voltage and current, it is displayed to be about 0.25W output power.

With this output power, since it seemed that it is too small, we decided to apply somewhat higher voltage to this vacuum tube.

It is reported to the test of the operating condition of this WE101D that it is satisfactory even if a Mr. Atarasi etc. experiments with a radio technical magazine and it makes it operate on somewhat higher voltage.

Originally, WE101,104,205 series is developed as a vacuum tube for a telephone, and as there is a life of about 50,000 hours or more by the usual busy condition, it is manufactured.

This can be taken for having taken the margin to the extent that it passes enough, considering structure of the vacuum tube, the size of a plate, etc.

There is an extreme difference compared with the life of a noncommercial vacuum tube being called around about 3,000 hours.

The area of the plate of WE101D is actually larger than 45 vacuum tubes with the plate dicipation of 10W.

We did about 250v load to WE101D as plate voltage from these points, and passed 13.5mA.

The plate dicipation was set now to about 3.5W.

As for the load impedance at this time, about 0.6W output power was obtained as a 5k ohm.

On the other hand, since the maximum output in the specifications table was considered as about 0.8W output power on the plate voltage 190V, the state as it is was used for WE104D.

By any type, the value of plate current tuned cathode resistance finely, the optimal value was calculated, and about 0.8W output power as a specifications value was obtained also in WE104D.

And we made WE101D and WE104D able to use both by changing cathode resistance with a switch.

As a result, although appearance was [ WE101D and WE104D ] alike, the characteristics and sound differed from each other greatly, and it turned out that it is a vacuum tube with which character is completely different.

They are well understood, if I have a lower table seen.

Moreover, compared with as for the sound quality, a difference being very great and WE101D being characterized by a masculine forcible energetic sound, WE104D gives the impression of a soft sound feminine and gentle to.

This thought that the sound of 45 was resembled somewhere.

This difference thinks that that those values of Gm probably differ greatly has influenced.

The difference in the gain of WE101D and WE104D thinks that it turns out that it is large also from a lower table.

Therefore, when comparing both, we have to change the position of the volume of a preamplifier sharply.

If it is heard in the same volume position, it will be audible so that volume may be too different and WE104D may be unimpressive.

Since WE104D somewhat has too few gains, we had better change an output transformer into a 2.5k ohm.

The impression of the amplifier which uses WE101D thought that it was the clear sound which a feeling of a lively motion has most in all the amplifier, such as WE205D of our company, 45, 300B, and was carried out distinctly except when a big sound is taken out.

This is miraculous as for extracting this output power.

I think that the influence of the power supply of the first non choke type to adopt with this amplifier is also great as for this.

With the usual amplifier, in order to remove the ripple of B power supply of the output power stage, a choke coil is used, but since this amplifier has small use current, it does not use a choke coil, but it forms a filter only by CR, and supplies B voltage.

Although it had been turning out that the choke coil has big influence on sound quality for some time, we experimented this time and were surprised at the large thing of the difference.

With the big amplifier of use current, although adoption of this method is difficult, we would like to adopt this system as future amplifier.

Moreover, using the type which enclosed the lug terminal type polypropylene capacitor of the U.S. Dearborn Electtrinics with the case of bakelite by the high strength epoxy resin at our company has also contributed to the cathode bypass capacitor of the output power stage greatly in sound quality.

Moreover, the vacuum tube of C3m of Siemens is adopted as this machine as a driver tube.

C3m is a pentode of the comparatively new design put on the market around 1968, and is the vacuum tube currently used as an object for a telephone of Germany.

Characteristics are very good, there is beautiful sound and noises etc. are few outstanding vacuum tubes.

At our company, they think that he would like to adopt it as future amplifier positively.

Although both WE101D and WE104D tested ST type and the tennis ball type, the tight sound whose ST type became tight well, and the tennis ball type were felt as the generous sound carried out calmly.

Although its form was pleasant, seeing a tennis ball type pleasantly, since it was expensive, when choosing out of sound quality, it was enough felt as it being with ST type.

Moreover, although both have a vacuum tube of old D number, and a vacuum tube of a metal base, a sample does not gather, and we have not tried listening yet.

When it carries out by accident, sound may be better than a vacuum tube of the second half.

The person who has needs to try.

If there are many output tubes as our company, he would like to sell positively, but since a vacuum tube is rare and acquisition is difficult, I do as the sale in those without an output tube for the time being.

I will search, if you connect with an output tube in hope.

Since this product is build to order, please confirm time for delivery etc. by E mail etc.

 WE101D(ST)   WE101D(Ball)  WE104D(ST)  WE104D(Ball)
Heater Voltage
4.5V DC
4.5V DC 4.5V DC 4.5V DC
Plate-Cathode Voltage
251V 189V 199V
Plate load impedance 5k ohm 5k ohm 5k ohm 5k ohm
Cathode resistor 2k ohm 2k ohm 3.5k ohm 3.5k ohm
Cathode voltage (bias voltage)
-27V -58V -56V
Plate Current 13.5mA 13.5mA 16.7mA 16.0mA
Maximam Power(THD10%) 0.69W 0.63W 0.94W 0.81W
Gain 21.9dB 21.5dB 15.3dB 15.8dB
Remaining noise 0.62mV,0.82mV 0.44mV,0.91mV 0.44mV,0.63mV 0.26mV,0.62mV
Frequency characteristic(-3dB) 21-27,000Hz 22-29,000Hz 12.6-38,000Hz 12.6-39,000Hz

A-08S WE101D/104D Version Specifications

output tube: -- WE-101D or WE104D

driver tube: -- C3m (a shielding case is removed and used)

Rectifier tube: 80

maximum output: -- WE101D: -- about 0.6W/8ohm WE104D: -- about -- 0.8W/8ohm

frequency characteristic: -- 22Hz-28kHz (-3dB)

remains noise: -- 0.4 to 0.8 mV

Impedance of an output transformer: Primary side 5komega, secondary side:8-ohm

drive system:CR combination, an auto-bias system