Hi Guys,
Apologies in advance if I break any rules...
Per my first post in introductions.., I inherited a DIY amp and 2 DIY speakers courtesy of my sisters ex BF. He gifted it to her a few years ago and she didn't want it when she was moving. So I took it.
It's been sat waiting for me to dedicate some time to it for the past 8 months. It looks crap, sounds awful and probably needs a lot of work. I suspect that some of the "speaker cable" is actually electrical wire and swapping this for something decent will probably have a positive effect on the overall sound quality.
Signal input is via a miniDSP 2x4 kit. I don't have the software to play with the sound profile. I believe you should get it free with the device, but only on the originating account, so I'll need to buy it.
This is the amp.
And the speakers are two home made cabinets each with unknown tweeters, and Seas Prestige H1224-08 L18RNX/P. There is no crossover in the speaker cabinets, bit instead wires come out of the bass ports and connect to one of the little things (amps???) screwed to the side of the chassis.
Can someone help to identify the parts in the pictures, tell me whether I'm working with anything decent. I suspect not, but surprise me... please.
Thanks in advance for your input, and let me know if you'd like any better quality pictures.
Apologies in advance if I break any rules...
Per my first post in introductions.., I inherited a DIY amp and 2 DIY speakers courtesy of my sisters ex BF. He gifted it to her a few years ago and she didn't want it when she was moving. So I took it.
It's been sat waiting for me to dedicate some time to it for the past 8 months. It looks crap, sounds awful and probably needs a lot of work. I suspect that some of the "speaker cable" is actually electrical wire and swapping this for something decent will probably have a positive effect on the overall sound quality.
Signal input is via a miniDSP 2x4 kit. I don't have the software to play with the sound profile. I believe you should get it free with the device, but only on the originating account, so I'll need to buy it.
This is the amp.
And the speakers are two home made cabinets each with unknown tweeters, and Seas Prestige H1224-08 L18RNX/P. There is no crossover in the speaker cabinets, bit instead wires come out of the bass ports and connect to one of the little things (amps???) screwed to the side of the chassis.
Can someone help to identify the parts in the pictures, tell me whether I'm working with anything decent. I suspect not, but surprise me... please.
Thanks in advance for your input, and let me know if you'd like any better quality pictures.
Well the unknown tweeters are unknown but the rest looks like good solid budget stuff.
it looks like the mini-dsp is being used as an active crossover, this feels left and right high and low frequency to the 4 LM3886 (I'm guessing) chip amps, which power the speaker drivers directly.
the mini dsp is decent, the chip amps are not shabby and the seas midbass is a good unit.
it looks like the mini-dsp is being used as an active crossover, this feels left and right high and low frequency to the 4 LM3886 (I'm guessing) chip amps, which power the speaker drivers directly.
the mini dsp is decent, the chip amps are not shabby and the seas midbass is a good unit.
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Thank you all for your help and guidance...
Not really sure where to start with this...
These are, I suspect, TDA7293/94. Thank you, I started to look up the amps you mentioned and then found markings on the amps I have here in an obscure place.
I'll likely do this over the weekend, stay tuned. And add pictures of all the gear.
This isn't gonna happen. We're not on speaking terms.
Not really sure where to start with this...
These are, I suspect, TDA7293/94. Thank you, I started to look up the amps you mentioned and then found markings on the amps I have here in an obscure place.
If you post a few pictures of the speakers we may be able to help identify what you've got
I'll likely do this over the weekend, stay tuned. And add pictures of all the gear.
This isn't gonna happen. We're not on speaking terms.
Whatever you do - DO NOT connect speakers directly without a crossover.
1 - tweeter should have a capacitor in series for protection. In case you might accidentally put bass through it. Protection capacitor for tweeter in active speaker
2 - currently the DSP feeds highs only to the tweeters. If you bypass the DSP you will blow the tweeter. Or if you have the protection cap then it will just sound crap with no crossover.
3 - if you bypass the DSP, you will want a passive crossover.
4 - try the amp only with other speakers (with crossovers) - then you know if its ok. Then you can experiment with the DSP and your DIY speakers.
1 - tweeter should have a capacitor in series for protection. In case you might accidentally put bass through it. Protection capacitor for tweeter in active speaker
2 - currently the DSP feeds highs only to the tweeters. If you bypass the DSP you will blow the tweeter. Or if you have the protection cap then it will just sound crap with no crossover.
3 - if you bypass the DSP, you will want a passive crossover.
4 - try the amp only with other speakers (with crossovers) - then you know if its ok. Then you can experiment with the DSP and your DIY speakers.
Thanks russc. I should probably create a small hand drawn diagram to explain what connects where, because I'm quite certain the speakers, and the tweeters are already directly connected to the amps. I'll either draw a picture, or take better pictures and annotate them. I suspect there is either a wiring fault here, or an amp has blown, because one of the drivers doesn't work, but the problem follows the amp the driver is connected to, not the driver itself.
EDIT: I am assuming the large circular thing is a torroidal transformer, and the large PCB with a the 6x RB32 caps is...? It has UPC1237 written on it, but Googling it returns pictures that look nothing like it.
In case you didn't know, I'm a newb.
EDIT: I am assuming the large circular thing is a torroidal transformer, and the large PCB with a the 6x RB32 caps is...? It has UPC1237 written on it, but Googling it returns pictures that look nothing like it.
In case you didn't know, I'm a newb.
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Yes the large circular (donut) thing is a toroidal transformer. The large circuit board with the six big caps will be the power supply.
It looks like you have four small amp boards, this will be left and right channels for each of woofer and tweeter.
The minidsp will have been used to do the crossover function (but may also have been used for room corrections) If it was also being used for room corrections, you need to get rid of that and start again for your room.
I've attached annotated image
Tony.
It looks like you have four small amp boards, this will be left and right channels for each of woofer and tweeter.
The minidsp will have been used to do the crossover function (but may also have been used for room corrections) If it was also being used for room corrections, you need to get rid of that and start again for your room.
I've attached annotated image
Tony.
Attachments
Thank you for that. So the two amps top and bottom left are connected to the woofers, the ones to the right are connected to the tweeters. Wiring aside, it seems fairly simple. Do you know of a free/open source software I can use to reset the DSP to factory?
I'd like to go down the route of internalising the crossover INSIDE the speaker cabinets and just have a single set of wires coming from the amp. How hard is this likely to be?
I'd like to go down the route of internalising the crossover INSIDE the speaker cabinets and just have a single set of wires coming from the amp. How hard is this likely to be?
The software is only $10?
<crossover INSIDE the speaker cabinets>
Not with the components you have.
The DSP is an expensive piece of kit so a shame not to use it (unless you have a better use elsewhere).
Safety first. You need a tidy and safe case layout.
1 – Mounting hardware for the transformer.
2 – Secure mains supply lead – fixed where it enters the case so it cannot pull loose.
These are easy as you only need a round hole and they tolerate different size cables.
Dome Head Flex Compression Glands TRS Cable Stuffing M12,16,20,25 - DISCOUNTS | eBay
The metal case should be connected to the Earth wire for safety.
3 – Your power supply board also includes speaker protection (the side next to the big caps) for I think 2 speakers. You could use this for your mid/bass speakers. Your tweeters will be protected by the protection caps you need to add.
4 – Add a pair of binding posts for each amp (8 in total); clearly labelled LH Bass, LH High, RH Bass, RH High. Also, label your amps inside the case similarly (avoids errors if everything is clearly labelled).
5 – Is the DSP a bare board to mount inside the same enclosure? It might well be a bit tight!
You will need some RCA sockets for your input source. Screened cable should be used between the DSP and the amps (can’t tell from the photo) and DSP to source.
6 – Bi-wire speaker cable (4 cores) avoids 2 separate cables to each speaker. No need for exotic cables.
<crossover INSIDE the speaker cabinets>
Not with the components you have.
The DSP is an expensive piece of kit so a shame not to use it (unless you have a better use elsewhere).
Safety first. You need a tidy and safe case layout.
1 – Mounting hardware for the transformer.
2 – Secure mains supply lead – fixed where it enters the case so it cannot pull loose.
These are easy as you only need a round hole and they tolerate different size cables.
Dome Head Flex Compression Glands TRS Cable Stuffing M12,16,20,25 - DISCOUNTS | eBay
The metal case should be connected to the Earth wire for safety.
3 – Your power supply board also includes speaker protection (the side next to the big caps) for I think 2 speakers. You could use this for your mid/bass speakers. Your tweeters will be protected by the protection caps you need to add.
4 – Add a pair of binding posts for each amp (8 in total); clearly labelled LH Bass, LH High, RH Bass, RH High. Also, label your amps inside the case similarly (avoids errors if everything is clearly labelled).
5 – Is the DSP a bare board to mount inside the same enclosure? It might well be a bit tight!
You will need some RCA sockets for your input source. Screened cable should be used between the DSP and the amps (can’t tell from the photo) and DSP to source.
6 – Bi-wire speaker cable (4 cores) avoids 2 separate cables to each speaker. No need for exotic cables.
Thanks again for your time. Totally understand that the software is $10, but if I don't need to spend money, I won't.
1 &2. The case is I think a 2U Mini Dissipante, which is incomplete. It doesn't have a front, or a top. So I suspect I'll need to replace it with something, unless I can have a local metal shop make up the missing pieces for me at a reasonable price The rear of the case is missing screws, but does have a kettle lead style power connector, it just isn't being used.
3. Thanks, I'll need to look into wiring this, and how to wire it.
4. Agreed. I'll need to get out the drill and have a little fun.
5. The DSP is a bare board, no case.
6. Yeah, I've previously used Blue Jeans Cable to purchase Canare 4S11 cables for my floor standers when I had a home theatre, they ultrasonically weld the cables to the banana plugs if you request it.
1 &2. The case is I think a 2U Mini Dissipante, which is incomplete. It doesn't have a front, or a top. So I suspect I'll need to replace it with something, unless I can have a local metal shop make up the missing pieces for me at a reasonable price The rear of the case is missing screws, but does have a kettle lead style power connector, it just isn't being used.
3. Thanks, I'll need to look into wiring this, and how to wire it.
4. Agreed. I'll need to get out the drill and have a little fun.
5. The DSP is a bare board, no case.
6. Yeah, I've previously used Blue Jeans Cable to purchase Canare 4S11 cables for my floor standers when I had a home theatre, they ultrasonically weld the cables to the banana plugs if you request it.
UPC1237 is a speaker protection chip. I can't quite see the board clearly but it will look like the attached image. There appears to be a relay on that board too which would be part of the protection circuit. Looks like it has been combined with the power supply ('RB32' - power supply caps).
Everyone was a noob at the beginning!In case you didn't know, I'm a newb.
Edit:
That board looks similar to one of these: NEW 63V 10000UF X 6 PCS Filter capacitor A6 Class A amplifier Power supply rectifier board-in Amplifier
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$10- for software is CHEAP when compared to the cost of passive components. A single capacitor could cost $10- and you might need a half dozen or so plus many other passive bits and pieces. I am just about to join the 21st Century myself and just bought my first DSP, the DSP alone was over $250- so I would say learning to use it would be the best way
Thread moved to Chip Amps.
Looks like the system was intended to use the MiniDSP as an active crossover for the speakers. So: Source -> MiniDSP -> amps -> speakers. You now just need to figure out which output of the MiniDSP is for the woofer and which is for the tweeter.
I see lots of mechanical issues in the amplifier. The boards are only supported by the chipamp itself. It doesn't look like the transformer is even mounted to the chassis. Neither is the power supply board. If you're going to use the amp, I'd fix those things first.
The good news is that those things are fixable. Within a weekend you could probably have a decent build.
Tom
I see lots of mechanical issues in the amplifier. The boards are only supported by the chipamp itself. It doesn't look like the transformer is even mounted to the chassis. Neither is the power supply board. If you're going to use the amp, I'd fix those things first.
The good news is that those things are fixable. Within a weekend you could probably have a decent build.
Tom
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