I just tested the SMT BTSB with balanced in driving balanced out and SE out. Everything checks out and the buffer is good.
This unit has a lot of uses. I think it will be a great volume pot buffer. Vunce has already used it as a low distortion buffer with gain after a 100R I/V in a DAC. I bet it could drive 250ohm high impedance headphones even (OPA1656 is good for 100mA but PSU is limited to about 35mA per channel). I might have to give that a test.
This unit has a lot of uses. I think it will be a great volume pot buffer. Vunce has already used it as a low distortion buffer with gain after a 100R I/V in a DAC. I bet it could drive 250ohm high impedance headphones even (OPA1656 is good for 100mA but PSU is limited to about 35mA per channel). I might have to give that a test.
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OK forgetting the passive parts of my request
A finished, stereo only, minimal version would be great.
But if anyone can assemble four sets to get 8 channels in a nice looking robust box, please let me know.
Both RCA for SE and either
3-pin XLR or 1/4" TRS "phone" jack/ plug for balanced, of course F input M output
Ideally could be integrated in the same box with a volume control, what do y'all think of this?
8ch (7.1ch) Multi-channel Audio Volume Controller Preamp (CS3310 x 4)
8ch (7.1ch) Multi-channel Audio Volume Controller Preamp (CS3310 x 4) | eBay
Only issue I have is the 12VAC input, I am off grid and don't know of a DC-to-AC inverter circuit with that output, needs 20W. Internally the boards use DC 30V, 18V and 5V, so could also do DC-DC conversion.
A finished, stereo only, minimal version would be great.
But if anyone can assemble four sets to get 8 channels in a nice looking robust box, please let me know.
Both RCA for SE and either
3-pin XLR or 1/4" TRS "phone" jack/ plug for balanced, of course F input M output
Ideally could be integrated in the same box with a volume control, what do y'all think of this?
8ch (7.1ch) Multi-channel Audio Volume Controller Preamp (CS3310 x 4)
8ch (7.1ch) Multi-channel Audio Volume Controller Preamp (CS3310 x 4) | eBay
Only issue I have is the 12VAC input, I am off grid and don't know of a DC-to-AC inverter circuit with that output, needs 20W. Internally the boards use DC 30V, 18V and 5V, so could also do DC-DC conversion.
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The BTSB buffer uses 12vdc input. It has on board 12v DC to +/-15v DC/DC converter.
An 8ch box would require qnty 4 BTSB's and any 12v 1000mA (Class 2) wall wart can power the whole thing. A lot of wiring though if making your own boxes. But that is what DIY is for.
If you use the TH version, you will save youurself having to wire up the input side as that is already XLR/TRS combo jack
An 8ch box would require qnty 4 BTSB's and any 12v 1000mA (Class 2) wall wart can power the whole thing. A lot of wiring though if making your own boxes. But that is what DIY is for.
If you use the TH version, you will save youurself having to wire up the input side as that is already XLR/TRS combo jack
Sorry I was not more clear.
Yes the 12V input on the BTSB is perfect for me.
I was talking there about having that issue with the 8-channel volume control I'd like to integrate with the BTSB
Going from 12Vdc to 12Vac cleanly without (much) EFI would IMO be a better solution if possible, rather than
a stock 120Vac inverter and then using the preamp's 12Vac output wall wart.
Yes the 12V input on the BTSB is perfect for me.
I was talking there about having that issue with the 8-channel volume control I'd like to integrate with the BTSB
Going from 12Vdc to 12Vac cleanly without (much) EFI would IMO be a better solution if possible, rather than
a stock 120Vac inverter and then using the preamp's 12Vac output wall wart.
No the engineer building these, 100x smarter than me, says the core circuit boards are IP-hiding potted with a black epoxy, very hard to figure out what's going where
Says the 12Vac is being rectified internally to at least three voltages between 5Vdc and 30Vdc
Here is the baseline unit he starts with
Hi-end CS3310 Remote Preamplifier / Stereo preamp with VFD display 4 way input | eBay
then adds another three of these
CS3310 three Input Signal Switch Preamplifier Board with Remote and Display | eBay
I would be willing to sponsor having one of the latter drop-shipped to you, if you think you'd be willing to help, send it on to me after if it doesn't work out.
Says the 12Vac is being rectified internally to at least three voltages between 5Vdc and 30Vdc
Here is the baseline unit he starts with
Hi-end CS3310 Remote Preamplifier / Stereo preamp with VFD display 4 way input | eBay
then adds another three of these
CS3310 three Input Signal Switch Preamplifier Board with Remote and Display | eBay
I would be willing to sponsor having one of the latter drop-shipped to you, if you think you'd be willing to help, send it on to me after if it doesn't work out.
Hi John61ct,
I am not quite sure what your question is. What does the BTSB Buffer have to do with what whatever CS3310 remote controlled preamp? And where is the box that only accepts 12vac come in?
Maybe there are three separate questions here? I am not sure what you want the BTSB Buffer to do?
I am not quite sure what your question is. What does the BTSB Buffer have to do with what whatever CS3310 remote controlled preamp? And where is the box that only accepts 12vac come in?
Maybe there are three separate questions here? I am not sure what you want the BTSB Buffer to do?
I would ideally like to be able to buy as close to a finished unit, or kit suitable for a noob
that integrates an 8-channel version of BTSB with a decent 8-channel volume control preamp. I am looking for feedback on, if y'all think this (first eBay link) might be a good way to go?
I need it to work (as close to natively) from DC as possible, as I have no mains/grid/ shore power AC available, and prefer to avoid inverters for devices that don't require them.
I do not have the means to work on component level electronics (yet, but do want to learn).
that integrates an 8-channel version of BTSB with a decent 8-channel volume control preamp. I am looking for feedback on, if y'all think this (first eBay link) might be a good way to go?
I need it to work (as close to natively) from DC as possible, as I have no mains/grid/ shore power AC available, and prefer to avoid inverters for devices that don't require them.
I do not have the means to work on component level electronics (yet, but do want to learn).
Do you need independent volume pots and they all need a remote control?
I think having 4 separate remote controls would be very confusing and they probably are not immune from crosstalk. That is, the one remote would activate all volume controls simultaneously.
Let’s assume you can have a manual dual gang stereo volume pot - a basic Alps RK09 for example.
A stereo volume pot would be needed for each channel of a balanced input. So that’s 8 pots. Each would need to be wired in between the input XLR/TRS combo jack and the BTSB.
You would need a power supply capable of supply 4 x 2w DCDC converters - a 10w 12v supply.
Then you would need to wire the outputs to the 8 XLR/TRS outputs. It’s a big project with lots of assembly and casework. It’s not hard but takes a lot of time. This is something you can do - it is just connecting stuff and soldering wires. Drilling holes on panes etc.
You might be able to find someone who can do this for you on DIYA. I’m not able to help you make the whole assembly as I juts don’t have the time. This is days and days of work.
I think having 4 separate remote controls would be very confusing and they probably are not immune from crosstalk. That is, the one remote would activate all volume controls simultaneously.
Let’s assume you can have a manual dual gang stereo volume pot - a basic Alps RK09 for example.
A stereo volume pot would be needed for each channel of a balanced input. So that’s 8 pots. Each would need to be wired in between the input XLR/TRS combo jack and the BTSB.
You would need a power supply capable of supply 4 x 2w DCDC converters - a 10w 12v supply.
Then you would need to wire the outputs to the 8 XLR/TRS outputs. It’s a big project with lots of assembly and casework. It’s not hard but takes a lot of time. This is something you can do - it is just connecting stuff and soldering wires. Drilling holes on panes etc.
You might be able to find someone who can do this for you on DIYA. I’m not able to help you make the whole assembly as I juts don’t have the time. This is days and days of work.
No, the first unit I linked to is a custom modified 8-channel version by that engineer, apparently located in California,
which he based off the other "assembled / finished" stereo-only implementations or similar which I linked to, which s/he orders from a Singapore manufacturer.
All 8 channels' gain / attenuation are adjusted together, to a given level, e.g. 0.5dB
So, only one remote.
Relative SPL differences between the center and sub, the front vs back speakers (or whatever), would rely on a relatively permanent adjustment at each power amp / powered speaker, usually an input attenuator,
right?
And no analog pot is needed, afaik? everything is self contained and digital via the CS3310
Datasheet: https://statics.cirrus.com/pubs/proDatasheet/CS3310_F1.pdf
After power off, volume level is stored to memory, so you don't have to set the volume level again at the next power on.
There is no input selection involved as with the original design, the "CH-1" on the front panel needs blacking out IMO.
_______
12V supply is no problem, even at many kW, whatever voltages (off grid, 300+A DC generation, charging EVs and eBikes)
> This is something you can do - it is just connecting stuff and soldering wires. Drilling holes on panes etc.
Sure I could, just my preference is to pay someone, and
I am still hoping not to require a mains inverter, that part is beyond me technically so far.
> You might be able to find someone who can do this for you on DIYA.
> I’m not able to help you make the whole assembly as I just don’t have the time.
Yes I was in no way expecting that, just looking for information, opinion & advice - from anyone willing to give that.
If anyone else think this would be an interesting project and is willing to discuss physically helping me, please speak up, here or via PM.
_______
If I kept the two functions in separate boxes, the wiring would be doubled, which is why I would prefer one integrated box if possible.
If they did end up separate, should the 8-channel BTSB be before or after the volume control in the chain? Assuming the context allowed for either choice of course.
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This offer was not tied to you "producing" anything, just giving feedback on its suitability, and maybe helping nail down the power layout to help me decide
how to best feed it, ideally via DC-DC from a LI battery pack, or worst case via a 12Vac inverter if possible.
Ok, I think I understand your question. You want to know how to power this Yuanjing CS3300 volume control thing from a LiPo etc.
I can see the photo clearly shows a center tapped transformer input and a full wave bridge rectifier IC and some smoothing caps followed by linear voltage regulators.
The reason the ask for a center tapped AC transformer is that they need dual rail voltages for the opamp. Typically +/-15v. The digital stuff can have another linear regulator to drop that to 5v or 3.3v.
Here is how you do this: get a Lipo step up converter to go from 3.6v to 12v. Then get a Murata or Meanwell 12v to +/-18v isolated DCDC converter.
You may be able to find a 3.2v LiPo in to +/-18v converter.
Feed the -18v into one of the AC inputs and +18v into the other AC input. Feed ground into the middle terminal. Since the unit is expecting AC it doesn’t matter which.
The bridge rectifier routes the correct polarity for you. The linear regulators drop the 18v to 15v (maybe 12v?) and it will work. I’m 99% sure it will. I’ve actually done this before on a cheap DAC that had a built in AC input. I just stuck my DC dual rail PSU.
If there was a transformer to convert the voltages it would not work. But that’s not the case here. Since they say 12vac at 1A we can estimate the power consumption at 12w for one rail and 24w for both. So you need a circa 25w +/-18v PSU.
Somehow get your 3.6v to 12v then 12v to +/-18v at 25w.
Use this to step 3.6v to 12v (or higher)
The unit may work fine with +/-15v into it. One of these can work straight from a LiPo.
3.7V 5V 6V 9V 12V to +15V/-15V DC DC Converter Step up Boost Dual Voltage Power | eBay
I can see the photo clearly shows a center tapped transformer input and a full wave bridge rectifier IC and some smoothing caps followed by linear voltage regulators.
The reason the ask for a center tapped AC transformer is that they need dual rail voltages for the opamp. Typically +/-15v. The digital stuff can have another linear regulator to drop that to 5v or 3.3v.
Here is how you do this: get a Lipo step up converter to go from 3.6v to 12v. Then get a Murata or Meanwell 12v to +/-18v isolated DCDC converter.
You may be able to find a 3.2v LiPo in to +/-18v converter.
Feed the -18v into one of the AC inputs and +18v into the other AC input. Feed ground into the middle terminal. Since the unit is expecting AC it doesn’t matter which.
The bridge rectifier routes the correct polarity for you. The linear regulators drop the 18v to 15v (maybe 12v?) and it will work. I’m 99% sure it will. I’ve actually done this before on a cheap DAC that had a built in AC input. I just stuck my DC dual rail PSU.
If there was a transformer to convert the voltages it would not work. But that’s not the case here. Since they say 12vac at 1A we can estimate the power consumption at 12w for one rail and 24w for both. So you need a circa 25w +/-18v PSU.
Somehow get your 3.6v to 12v then 12v to +/-18v at 25w.
Use this to step 3.6v to 12v (or higher)
The unit may work fine with +/-15v into it. One of these can work straight from a LiPo.
3.7V 5V 6V 9V 12V to +15V/-15V DC DC Converter Step up Boost Dual Voltage Power | eBay
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You can use an RCA female to TS 1/4in (mono) jack adapted. This will ground the ring (-ve input) with the ground (sleeve) and enable the signal to drive just the +ve (tip) of the balanced input.
For example...
Plug this into the combo XLR/TRS Neutrik jack.
https://www.amazon.com/dp/B000068O3S/ref=cm_sw_r_cp_api_i_avYKFbK4CD5V0
Or use a mono RCA to TRS male cable like this:
https://www.amazon.com/dp/B083R4DL5N/ref=cm_sw_r_cp_api_i_NwYKFbAH8BHPT?_encoding=UTF8&psc=1
Or if doing it by hardwire soldering flying leads: ground the -ve balanced input. Connect input SE signal to +ve balanced input.
For example...
Plug this into the combo XLR/TRS Neutrik jack.
https://www.amazon.com/dp/B000068O3S/ref=cm_sw_r_cp_api_i_avYKFbK4CD5V0
Or use a mono RCA to TRS male cable like this:
https://www.amazon.com/dp/B083R4DL5N/ref=cm_sw_r_cp_api_i_NwYKFbAH8BHPT?_encoding=UTF8&psc=1
Or if doing it by hardwire soldering flying leads: ground the -ve balanced input. Connect input SE signal to +ve balanced input.
I am listening to my Alpha Nirvana amp (39W Class A) powering my 10F/RS225 FAST TL's tonight. I decided to see what the BTSB sounded like driving a nice low distortion Class A amp. With balanced input provied by a Focusrite 2i4, and 6dB gain setting on BTSB Buffer, and SE output, the BTSB really sounds great in this setup. Very neutral but the overall clarity and bass dynamics seems better. Very enjoyable - I think the OPA1656 is a really super sounding opamp. It's like the proverbial "wire with gain".