2.1 TDA2050/2030 amplifier project for a virtual pinball

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi all,
My first post here. I have been reading a lot of great and helpful posts here. I'd like to hear your opinion regarding my quest for Class AB 2.1 amplifier. So without a further due; here's my query:

I am planning a virtual pinball cabinet. One of the things I am after for that project is to replicate the sound system quality inside these cabinets.

Few facts first:
One of thr best Williams/Bally pinball company sound system boards was the WPC DCS which had mono sound source and consisted of the following topology:
- 5.25" 4ohm 25w midrange speaker (inside back box)
- 3" 4ohm 15w tweeter speaker (inside back box)
- 6" 4ohm 25w subwoofer speaker (inside cabinet)

- A pair of TDA2030av 18w (@4 Ohm) audio amp ICs in a two-channel arrangement

- The sounds generated by the system are fed into a two-way crossover network with a crossover frequency of ~300 Hz.
- Low frequency output of the crossover network drives the cabinet speaker (subwoofer) through one amplifier.
- High frequency output drives the back box speakers (midrange and tweeter speakers) through a second amplifier.
- Williams used two different speakers in the back box: a midrange on the left side, and a tweeter on the right side, which are wired in parallel, with a 10 MFD non-polarized capacitor in series with the right speaker (the tweeter); the capacitor is used to block lower frequency sounds from being reproduced by the speaker. Technically, the capacitor forms a first-order high-pass filter with a crossover frequency of 4000 Hertz.


Speakers i am currently have for the project (Pulled from an arcade cabinet, working):
For backbox speakers, i have:
A pair of identical "Challenge-Electronics 5412px" 5.25" coaxial 4 Ohm, rated 15w (30w max) speakers for stereo games as well. Should be enough to cover mid and high spectrum range (not looking for too bright sound anyway)
DATASHEET/SPECS:
https://www.challengeelectronics.com/downloads/speakers/square/5412PX.pdf?cc=18209

For cabinet low frequencies i have:
Goldwood GW-208/4 8" Subwoofer 4 Ohm, 100w RMS (200w max)
DATASHEET/SPECS:
Goldwood GW-208/4 8" OEM Woofer 4 Ohm


Objectives:
- 2.1 amp based on TDA2030 or TDA2050 (More watts than the TDA2030, but nevertheless the same characteristic i'd believe)
- Having the same amplification characteristics (i want that lo-fi (lacking for a better term) audio quality with juicy mid and bass used originally in these pinball tables)
- No pop/clicks on power on and power off of the amplifier - So no class D amplifiers for me.
- Knob potentiometers to allow the control of: Subwoofer output volume, Subwoofer crossover frequency control (low pass), L/R (back box) speakers volume, L/R (back box) speakers crossover frequency control (high pass)
- Because my subwoofer impedance is rated at 4 Ohm, the 2.1 amplifier shall not have a BTL implementation for the sub output but rather a single amplifier.
- If the crossovers could be 1st order only it could be closer to the original sound character in those pinball tables as these implements only a 1st order low-pass/high-pass filters/crossovers


Here's what i came across so far for the project:
- TDA2050 3 ICs amplifier for 2.1 channels (25W x 2 + 38W), no BTL:
Buy Products Online from China Wholesalers at Aliexpress.com
Concerns: Not sure about the build quality and the components; Not sure about the potentiometers purposes (these Chinese sites always mislabel the knobs purposes until you really put them up to test)


IE Transformer (220 to 12-0-12 50w):
Aliexpress.com : Buy Power transformer double 12V 50W 220V 12V 0 12V 2A center tap power amplifier front from Reliable Transformers suppliers on peony Store
Concerns: Is this transformer "fair enough" for this audio application ? Assuming this transformer will be mounted not too close to the audio amplifier board.



Need your advice here:
- Buying a 1st-order crossover board - 300Hz low-pass for the subwoofer speaker.
- Buying a 1st-order crossover board - 300Hz high-pass for the stereo pair of the back box speakers. (so need two of those)
- Are there any other alternative for this 2.1 TDA2050/2030 based amplifier board linked above? I know there are few recommended amplifier boards vendors such as Sanwu, Sure electronics....But i have not came across 2.1 TDA2050/2030 based amplifier solution by these vendors. Perhaps you could enlighten me with other reliable vendors ?

Assumption: The 2.1 amplifier board does not provide a flexible crossover functionality for either subwoofer or back box speakers,
Should i put a crossover before the inputs or after the outputs? Are there cheap flexible crossover boards to add to an existing amplifier boards?


I am trying to keep cost sane as much as possible for this project.
Thanks in advance for every useful and helpful advice :)
 
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.