It has stocked with the toy and TR-10RDX of famous the sound is good in the homepage of certain and mini-FM.
It stocked with TR-10RDX Age of earliness

Nobody doesn't take notice and be in the junk box with garbage.
It cannot be helped because a thing reeling moderate

However, the sound of this toy is still good.
why that it says will.
 
 

The impression that hears the sound of ??
TR-10RDX though it is no use of the straight evaluation of the toy of "398"

About a low region first of all, of sound "Sukasuka" is not reproduced, and it doesn't become flat feeling even if it raises it as BASS of stereo AMP is full. It is a sound with which the nose is blocked if it often hears it though a high region is feeling deceived with "Zarazara" No sound of the telephone that a high region and a low region are cut if it says simply.

It smells ..the religion.. or the world of audio is interesting because it does though it is thought that no one in such a sound takes notice.

This time, it is a project said bringing the sound of TR-10RDX to a sound that manages to be straight close and seeing.
 
 

The basis of the sound is Flat First of all, the frequency response is taken, and it what kind of thing sees and it sees.
 

 

I think that it can immediately understand the meaning as for the sound of the telephone if it sees whether it is a person who understands.
frequency response falls fast when seeing for every 200Hz and falls by 20Hz by about -15 the dB.
-15dB..no 200Hz-1.8dB/100Hz-3dB/50Hz-7dB/20Hz it how.
The BASS volume of AMP is squeezed, the bass doesn't go out of more terrible than the cut state, and it is possible to consent.

It falls in 4kHz-1dB/8kHz-2dB/10kHz-2.5dB/14kHz-4.2dB/15-4.8dB from which the high pitched sound doesn't come out from about 2000Hz by centering on 1000Hz either. Neither the bass nor the high pitched sound go out, and because it is telephone the reality.
 
 

Then, do you improve it from a low region ?

Because the cause is capacity shortage of the coupling capacitor of the input, it changes to capacity to which a low region passes C1, C3, and 0.1uF of TR-10RDX.
It might be good in the input impedance in the capacitor of about 1uF. Anything is OK if there is capacity of 1-10uF.

C1 and C3 are changed to 4.7uF on hand for the time being.
The capacitor that exists in the photograph below is C1, and C3.

The low region characteristic is improved like image (a) frequency response after it changes below.

A low region rises like image (b) frequency response l after C2 and C4 are changed above.
It interferes with the cause because the design of the loop filter of PLL is negligent.
"Yabai" and a low region are kicked, and it attenuates or it interferes in the filter time constant, and a low region rises the rise of the design of the loop filter of PLL.

TThe time constant of the loop filter of PLL of TR-10RDX doesn't obtain an excellent low region characteristic it seem to be in about 21Hz because there is not improving it with to our regret PLL great.
The sound that rots temporarily makes to the thing, adds not going
4.7uF C1 and C3 by the bass, and adds the capacitor of 0.033uF to the change, C2, and C4 with Para.

The low region characteristic improvement plan ends cheating frequency response by the capacity of C2 and C4.

The low region characteristic was improved to frequency response target, and, however, tone quality is another dimension.
 
 
 
 

A low region has been improved and the following will see the high region side attacking it.

Though there is a problem in the time constant of Pre-emphasis When the frequency response is seen, it seem not to be in the problem only of the time constant, and the capacity of the capacitor of the time constant of temporary Pre-emphasis is changed and I will see a rapid getting depressed of 10KHz or more.

The capacitor that exists in the photograph below is capacitor C5, and C11 of the time constant of Pre-emphasis.
When it is a reference of IC manufacturer, it tests from the vicinity of 330pF with 2200 pF because the capacitor of the base of TR-10RDX is unsigned 50ƒÊs what by uncertain capacity, cutting, and the trial.
Let's add the capacitor to the arrow part in the photograph between earths and make it to the seen frequency response thing.
 

frequency response in a high region is somewhat improved by adding +330pF like image (c) frequency response below. It becomes like (d) because of the addition of +450pF.

However, a rapid getting depressed of 10kH or more seems not to be good though it was somewhat improved. frequency response begins to rise from about 2kHz by adding the capacitor of +680pF and the time constant of Pre-emphasis collapses.

It becomes a considerably hard sound, and the amplifier is internal organs in TR-10RDX for the low-pass filter the inside of the audio amplifier the problem of the favor.
BH1416F used frequency response target in case of +680pF here seems to be not a rapid getting depressed of this 10kH or more in the constant of the low-pass filter of TR-10RDX correct.

The added capacitor is 450pF? now. 470pF title is good.
 
 
 

The sound of TR-10RDX is opened from the sound of the telephone by remodeling the above-mentioned. The evaluation of the sound to which the frequency response is somewhat improved ??
 

Well, where of TR-10RDX shall I attack when the site will be updated next time ?

Flat first of all, the basis of the sound is necessary to flatten it as for the frequency response.
A high region is improved the attack per LPF of 15kHz because of the stage before the long ages very saying because of there is no frequency response in flat the sound.
Be not impossible of the improvement if PLL manages not to be done in a low region. ??
I want to put even only the frequency response at least in the standard apart from tone quality.�iHi...bakusyou!

Please send it if there is opinion hope for the TR-10RDX remodeling project.
 
 

Work around the time constant of Pre-emphasis of capacitor C5 and C11 is extremely severe, and go in the soldering iron etc. , please with scrupulous care by the use of the thing that a special temperature is managed. Please do not hear at all, and execute all the complaints of the accident and the damage, etc. that happen because of remodeling in the self-responsibility.
 
 
 
 
 
 

 
 
it is mini FM Toy transmitter /TR-10RDX - What do you want to do with a toy of this "398" FM transmitter ?