Portable DBX, deal or no deal?

I have asked around on the tapeheads forum about ways in which i can improve the quality of my recordings and my set-up.
After some further research I have boiled it down that my double tape deck has dbx therefore I should buy a portable dbx decoder.

I have found a seller from the united states who is willing to ship internationally, the decoder is of course the dbx ppa-1


...

Main specification
-Dynamic range: 90dB
-Frequency characteristic: 50Hz-15kHz 1.5dB (dbx Type II decode)
-Distortion factor: 0.3% or less (1kHz)
-Input impedance: 180 ohm
-Output impedance: 3.3 ohm
-Input connector: 3.5mm miniature stereo plug
-Output connector: 3.5mm miniature stereo jack
-Power source: 2 PIECES AAA SIZE 1.5 VOLTS
-Drive time: It differs 20 - 30 hours (continuation), depending upon NR type
-Size: 11.13.23 cm

Has anyone else ever used it? Is it worth it? the seller is asking for 30 dollars and I will have to also spend money on the USPS international shipping fee, of which I have no idea how to estimate.

 

It's quite rare and certainly cheap despite offering improvemtns that are a bit of a grey area.

 

What do you mean by gray aera if i may ask?

 

It is surely an interesting piece of tech, but do you think the problem in your recording is too much hiss from tape ?
DBX, like Dolby, is a dynamic compressor/decompresser so that recorded levels on the tape are always optimal to increase SNR, but, like Dolby, it requires correct playback levels and a good frequency response. Any mismatch will result in sound artefacts (too bright, too muffled...).

A decent type II tape with correct bias and levels (not too high) will yield a good recording.
Hiss on a type II is tolerable without Dolby and hiss is also an essential part of the cassette

 

DBX offers a very specific solution. If your set-up doesn't need this solution then I suggest it won't bennefit you much.

 

I also think this piece of hardware isn't the real answer to the problems you might be encountering.
Now you shouldn't be feared to buy it at that price, you'll certainly be able to sell it afterwards if you aren't satisfied. I, for one, promise I would buy it to you at that price! ;-)

 

I can't really change the bias on my deck as it is a double deck without any bias controls. So that limits what I can do with my recordings. Also my deck doesn't have HX-Pro.
However my double deck a pioneer st-s99wr already has dbx as part of the NR's as well as Dolby B and C.
Dolby C is a bit specific and sounds muffled on my everyday walkman my aiwa hs-pc202 mkii.
Also dolby C when played on other walkmans like my d6c sounds muffled on the mid to high frequencies.
The issues I have with dolby C stems from the fact that it's not all that stable on my Aiwa. I don't really need to use dolby B, the hiss only affects low frequencies.
I did the math and have found that if I record on a normal cassette using dbx, I have a dynamic of range of 110db which is still higher then if I record using a metal cassette on a wm-d6c with dolby C.

The only thing i don't really understand from the specs sheet when comparing them both is the pioneer's frequency response (i don't know the difference of a -20db recording and a -o db recording)

 

If you can't properly adjust bias and sensitivity my suggestion is to stay away from any NR system, they will make recording's sound worse.
With a fixed bias tape deck, you should buy only one type of tape (one model from one brand ..) and calibrate the tape deck for that specific tape. That means adjusting the internal potentiometers for bias and rec level so that the recordings are correct both in terms of frequency response and sensitivity.
Anyway, as a general rule, if you are uncertain of bias, recording without NR system will yield a better sound.

110 dB of dynamic range is a huge number, roughly the difference between a completely quiet room and an airplane taking off. The specification of the tape deck calls for 92 dB (which is still rather unrealistic to me) but more in line with the numbers boasted when dbx was presented in the late 70's

That refers to the level of the recorded signal on tape; typically the frequency response is specified at -20 dB VU where the tape is far from saturation; at 0 dB (VU scale ?) you are close to the tape MOL/SOL and frequency response is much more limited. That is also more dependant on the tape rather than the deck, not sure why Pioneer included that spec.

 

If it were me, Id try to source a better cassette deck. This DBX Silencer is more of a band aid than an enhancement in your current situation. Like all hifi, the thing you want to remember is Garbage in = garbage out.

The Aiwa 202 is a great piece of kit. Have you ruled out a head alignment issue between your deck and portable?

A decent deck, using decent tape should render great results that negate the need for any NR in my opinion.

 

To be fair I am using SACD Quality garbage in. Also the bidding ended up at 102.5 dollars so I'm out, I don't need a band aid i need at the very least super glue and duct tape.

I did a test with a new mix-tape: One recorded on a SONY AHF 60 with dolby C, the other a TDK AR 60 without dolby.
The sony tape was recorded with my WM-D6C, which probably has been serviced before, bought it from walkman1984.
The aim of the test was to get a better understanding of the frequency response of the double deck.

After testing and listening it is clear that the double deck has a better Dolby C frequency response.

(On a side note the Sony tape when recording without dolby sounds atrocious;
as though it's missing the mid frequencies as well as sounding quite bright on the high frequencies, I don't think this tape aged very well, but I did record from the double deck so the fixed bias is something i need to take into account, maybe I should have done the test on the D6C seeing as they are both Sony products)

I was testing it as well on my Aiwa, yet sadly I think it died on me;

On the left channel there was some kind of humming that was unheard of previously.

On the right channel, a scratchy pot that scratches at specific volumes, not randomly.

After that it just wouldn't turn on with the batteries... I don't think the warranty covers this ;_;


Trying to give an alcohol bath (90% denaturated alcohol) is usually what fixes 75% percent of all my electronic problems, i care too much about the aiwa to gamble on this one.

I'll save money and once I'm down with a job and out of university I'll buy a 3 head deck (and a better dac) to blow my current deck out of the water.
I'm thinking of either getting a Nakamichi bx-300 or a Bang & Olufsen Beocord 9000. (hopefully when I can afford those the prices will remain reasonable)

For the meantime, I'll be spending money repairing the Aiwa.
I'm assuming Sony repairmen can take care of Aiwa products. If so I may found one near where I Live

 

My old two heads AIWA had adjustable bias and there was a sticker with the indication of the bias settings for most common tape brands and types (all Japanese, no less). You could infer the reference tape by looking for the tape in the zero position. Moreover, tape deck manufacturers were expected to calibrate their decks using IEC standard tapes (BASF type I, TDK SA type II, ...) but as an old quote says: “The good thing about standards is that there are so many to choose from.”