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작성일 : 05-07-19 08:13
[Kirungs GM70 SE] [re] 모찌님, 위의 회로 앰프 설명 (번역문)
 글쓴이 : J
조회 : 2,176  



번역기로 돌렸는데 완벽하지 않습니다...


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Recently we increasingly more began to gravitate towards to the large sound.
By the "large" we will imply the open sound of real sizes with the maximum dynamic range.
Certainly, first of all this sound is determined by large acoustic systems, in essence horn.
I.e., dynamics and overall sizes this ACE large - and sounding is large.
The laws of physics you will not deceive.
But also amplifier also influences the dimensions of sound.

We were set as a goal to make a vacuum-tube amplifier for the large sound.
Let us transfer those principles, which be the basis of our design.
Their major portion proclaimed already A. m. likhnitskiy (in further AML) [ 1 ].
This is how they appear with our it dobavleniyamiopredelyaetsya by large acoustic systems,
in essence horn. I.e., dynamics and overall sizes this ACE large - and sounding is large.
The laws of physics you will not deceive.
But also amplifier also influences the dimensions of sound.

Electrical amplifier circuit must be maximally simple.
Amplifier must not contain negative feedback.
All cascades of strengthening, as far as possible, must be transformer [ 2 ].
All lamps, as far as possible, they must be the filamentary triodes,
which work in the class A with the clamp bias. All electroelements, jumpers and solder
must be thoroughly selected for the purpose of the complete harmonization of system.
There must not be parallel connections, including of lamps (even triodes in one balloon).
Each user of electric power in the amplifier must have his power source.

The power of vacuum-tube amplifier for the large acoustic systems,
according to the recommendation of their developers, must be not less than 50 honest watts
(at least to 3% of nonlinear distortions).
For solution of this problem most be suitable the foreign 2yy-yy and 8yashch-yy triodes,
and also our domestic powerful modulator triode GM70, which, with the same basic parameters as two first,
possesses the b.ol'shimi emissive possibilities. Its- that we selected.

It seems, impression is created that we against the single-cycle amplifiers.
No. Single-cycle circuit - ideal diagram.
But so that the principle of single-cycle nature would show itself from the best side,
it must be used, in our opinion, with the power by beginning with 25 W
(i.e., with the use only of afore-named triodes), also, without the use of parallel lamps.
Two football players cannot simultaneously strike one ball! They showed our experiments:
any parallel connection of lamps significantly decreases the transparency and the dynamics of sound.
Rumor - this is principal criterion.

Do not only think that we speak against existence of the
"club of the amateurs of single-cycle amplifiers to 1 W" (or to 3 W...). To each its.
We now speak about the large sound.

So tempting to connect the advantages of single-cycle and push-pull circuits.
Indeed in our case, using a "transformer idea",
this is possible!
Why many do consider that the single-cycle amplifier does sound better than double measure?
From our point of view, in essence this is connected with the realization of phase-inverting cascade.
The usually utilized phase inverters - are asymmetrical [ 3 ]. Let us transfer basic.

Phase inverter with the anodic divider (self-balancing inverter stage with the common cathode).
The main disadvantages: high output resistance, the presence of feedback and that that the way,
passed by signal to the inversion, can be various
(if negative output signal is obtained as a result of the passage through one lamp,
then positive - through two).

Phase inverter with the divided load.
Deficiency - large asymmetry of the output resistance of anodic and cathodic arms and presence OOS
respectively on the current and the voltage.

Phase inverter with the cathode coupling the deficiencies:
high output resistance and difference in output characteristics
(first triode it works in the regime with the common cathode,
while the second - in the regime with the grounded grid).

Paraphase (self-balancing) inverter.
The main disadvantages the same as into 1 and furthermore the signal for the inversion is obtained
as a difference in the anode voltages.

From all these deficiencies the transformer,
which has secondary winding with the outlet from the middle is free
(or two identical secondary windings).
Besides this, such paraphase transformer completely ensures the agreement
between the cascades on resistances and stresses
(one ought not to forget that the stress of rocking for GM70 on the order of 100 v).

In this case does not occur increases of the quantity of electroelements in the chain
(as it would occur with the use of any inverse diagram),
indeed transformer is simultaneously the plate load of the driver (predmoshchnoy) lamp,
which works in the class A.

All this predetermined the use by us of a paraphase transformer
in the push-pull amplifier for the large sound.
Fig. 1. the plate characteristics

Let us give data of the regime of the work of lamps GM70 in the class A in the output stage.
Regime standard [ 1, 4 ];
therefore let us give the results of calculations on the basis of the family of the static plate
characteristics of lamp (Fig. 1).
According to reference data, the maximum permissible for GM70 power of scattering
on the anode Of ra.dop = of 125 W, the maximum permissible voltage on anode Ua0maks = of 1500 v.
from the experimental data plate resistance Ri = 1630 Ohm let us take voltage on anode Ua0 = 950 v,
that there is much lower than maximum. Then the quiescent current Ia0 = of 0,9 Ra.dop/.Ua0? 0,12 A.

After noting the position of quiescent point on the family of static plate characteristics
(point o in Fig. 1), let us find that it does correspond to the stress of negative displacement
on grid -100 v,
therefore, the maximum amplitude of the voltage of signal also can be undertaken equal to 100 v.
in this case the instantaneous value of grid voltage will vary in the limits from 0 to -200 V.
soprotivleniye the plate load of triode Rв = 3Ri? 4900 Ohm through the quiescent point
we carry out load straight, appropriate y/.Rв, and with the intersection with the characteristic
we find maximum current for Uc = 0: Imaks = 0,24 A, and minimum current for Uc = -200 v: Imin = 0,03 A.
otsyuds is output power of one lamp R~? 0,125 rв (Imaks - Imin)2 = 27 W after accepting
THE EFFICIENCY of output transformer h = 0,93, let us determine
the output power of amplifier Rvykh = 2 h X r~ "50 W.

As we spoke above, this powerful triode, as GM70, in contrast to its small fellows can long time work
with the grid currents, which appear with the positive instantaneous voltages of control grid.
Peak-plate current is no longer limited to the characteristic of lamp for Uc = 0,
and operating region begins to be moved to the left from this curve.
In this case the lamp passes from the regime A into the regime A2.
In this case the output power of amplifier practically two grows and it increases by its EFFICIENCY.
The observed growth of nonlinear distortions
(proceeding because of the grid currents) can be reduced to minimum by applying
the low-resistance source of input voltage for the output stage -
paraphase transformer ideally is suitable for this.
Under these conditions in the secondary winding of paraphase transformer
the power is expended on the grid currents;
therefore driver cascade it is necessary to examine also as driver amplifier.

The electrical circuit of one amplifier channel is given in Fig. 2.
It is sufficiently simple. Triodes GM70 are loaded to the sonic transformer" SPb S TO70PP ".
As the driver lamp we selected famous 300B of production "Svetlana",
loaded to the paraphase transformer "SPb S IT300PP".
The first cascade, for the b.ol'shey universality
(since not all sources or preamplifiers have low output resistance),
it is made resistive-capacitive on most honest on the sound lamp 'N8S.
The versions of this lamp selected on the sounding having on bases 7 (seven!)
the dies of the military inspection of quality.
However, they knew how to make earlier...

As can be seen from diagram,
the power source is built so as to obtain the complete decoupling of all cascades,
and also filament chains and bias circuits,
which is extremely important for obtaining the high-quality sound.
By this the minimum of the leakage currents in the lamps is reached,
and furthermore are removed concealed "alternate paths" and parasitic OOS.
Also this makes possible for us to use in the diagrams of filtration
the neelektroliticheskiye oil-paper capacitors of the not very great capacity,
which in contrast to the electrolytic are symmetrical for the variable signal.
This does not relate to the chemical capacitors "Black Gate"
(here they they stand in the critical place),
that is differed in the sounding from the usual "electrolytes".
True, with the observance of all these conditions the weight of power unit for each channel
proved to be about 30 kg and amplifier it was necessary to carry out in the form of two monoblocks,
with weight of 50 kg each.

SPZ - this is the block of the system of smooth starting (nevertheless almost kilovolt in the anode).

Assembling and installation of amplifier are simultaneously and the beginning of harmonization
on sounding of entire circuit.
Everything is here important:
where must be "earthen" point, what are selected conductors and which their length,
what solder and as by it to solder, and even phasing not only on the constant,
but also along alternating current.
Are selected on the sound all elements of installation, including the transformers,
whose sounding is determined by the secrets of their construction,
by impregnation and quality of the material of magnetic circuit and winding wires.

After carrying out installation and after neglecting amplifier,
we obtained only basis.
After hearing this basis,
AML said: "here now, on this basis, it is possible to begin to work directly at sound".
It reached from the briefcase the glass jar from under the coffee "chibo",
at which lay "secret provodnik"y.
After its start in the specific place in the sound arose the aroma of sounding
the tube receivers of the 30th it was annual and some special magic.
It was desirable to listen to and to listen to long ago the already crowded after-taste working test disks,
to say nothing of in anything other.
In this case the middle became more transparent and it is more detailed,
and bass is deeper and it is at the same time clearer.
But indeed we for the installation used also not simple copper -
and LC, and OFC, and С, and in the teflon, and the most famous firms!

By hours we crept on the floor around the monoblocks, resoldering, turning over their tyazhelennye housings.
Everything influenced sound!
Some facts seem us not explained.
For example, in the inverted flight position amplifiers sounded clearly more quietly,
also, with the reduced dynamics.
To the normal position the sound was thrown open with their installation,
it became more loudly, it is clearer and it is more dynamic.

The one who in earnest was decided to the production of this amplifier,
must use the recommendations, led in "AM" № 4 (9) 96 and № 2 (13) 97, and also
"PTB with the work on the electrical devices with a voltage of up to 1000 v".

The technical parameters of the obtained amplifier, let us name it "SPb S T70PP", that follow:

Load resistance 8 Ohm
The output power in the class A2, limited by the value of nonlinear distortions 3%
Continuous average output power in the class A of 50 W
Coefficient of general harmonic distortions with continuous average output power 1,8%
Input resistance of 100 k
Sensitivity with continuous average output power 1,5 v
Overall dimensions (width X depth X height) of 400 X of 550 X of 300 mm

After the objective data about the amplifier let us pass to the subjective.
In our view, sound came out not "lamp",
if we have in the form the negative understanding of this definition,
which implies the amorphism of bass, small dynamics and power.
But also not "transistor", that is considered mechanical, cold and formal.
SOUND came out.

In the hearing all well-known patriarchs of audio participated and expressed their admiration by sounding.
Perhaps that remained unknown the opinion of Herman abendrot, Wilhelm Furtwangler and Artur Toskanini.

Literature
A. likhnitskiy. From the "transistor" sounding of amplifier "surf" to the "lamp". - - "audioMagazin",
1996, № 1, s. 53. V. Medvedev.
Transformers in the channel. - - "audioMagazin", 1998, № 3, s. 133.
R. lendi, D. Davis and A. Albrecht. Reference book of radio engineer. L., Gosenergoizdat, 1961.
G. S. tsykin. Amplifiers of electrical signals. M., "energy", 1969.
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. 05-07-19 08:30
 
  출력트랜스가  4.9K+4.9K : 8 인듯.......
 
 

Total 71
번호 제         목               글쓴이            날짜 조회
71 [Kirungs GM70 SE] 100TH 함 만들어보자 (5) 모찌 19-11-18 1195
70    [Kirungs GM70 SE] 100TH 요거지요 (2) 허브 19-11-20 1082
69       [Kirungs GM70 SE] 100TH 요거지요--ㅎㅎ (2) 나루터 19-11-21 1100
68 [Kirungs GM70 SE] DC 10V /10A를 사용할때 어느정도 규격의 다이오드를 사용해야 (8) 모찌 10-02-16 2629
67 [Kirungs GM70 SE] 833를 구입하게 되었습니다. (11) 모찌 10-02-04 2558
66    [Kirungs GM70 SE] 히터불을 켜봅니다. (5) 모찌 10-02-05 2256
65 [Kirungs GM70 SE] 833A 싱글.. (11) 모찌 09-07-06 2897
64 [Kirungs GM70 SE] 독일 또라이..가 보내온 메일.. (9) 모찌 05-10-13 2709
63 [Kirungs GM70 SE] 이트랜스의 견적을 알려주시면.. (11) 모찌 05-07-17 2366
62    [Kirungs GM70 SE] [re] 모찌님, Tribute 트랜스 알아보셨나요? (118) J 05-07-18 11247
61       [Kirungs GM70 SE] [re] 모찌님, 위의 회로 앰프 설명 (번역문) (84) J 05-07-19 2177
60          [Kirungs GM70 SE] 방방님 GM70/PP의 스펙은 다음과 같습니다. (2) 모찌 05-07-19 1777
59 [Kirungs GM70 SE] GM70의 소리변화에 대한 비밀 (3) 모찌 05-07-11 2484
58 [Kirungs GM70 SE] [gm70] 을 새삼스레 들어보며.. (10) 모찌 05-06-28 2383
57 [Kirungs GM70 SE] gm70 연휴에 불땜 (1) 모찌 05-01-03 2228
 1  2  3  4  5  

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