ComClone - Has anyone got it working reliably?

[DanSteely]

Hello Brian/Boatman/Timsabre/Everyone:

 

Can you please factor in connectivity for PC type headset utalising 3.5mm jacks, or would it be more logical to chop off the jacks and solder on an XLR... I guess either way there would need to be some mod to accommodate the e.g. different microphone technology.

 

My sincere thanks to everyone who has contributed to this thread.

 

Dan

 

P.S. No response from Mr Crowley so far..

[Brian]

Which bridge amp chip are you thinking of using?

TPA3122 looks good. Class D, £1.53 in small quantities, 24v rail no problem.

 

I also have the full version of Easy PC (V16) if you're thinking of a co-operative venture and have PCB footprints for Neutrik NC3MAAH & NC3FAAH2 which I needed for my cuelight system.

Certainly a second set of eyes would be good.

 

Can you please factor in connectivity for PC type headset utalising 3.5mm jacks, or would it be more logical to chop off the jacks and solder on an XLR...

From a compatibility and reliability viewpoint it'd be easy to swap to XLR. However, fitting a 3.5mm jack would only need a few wires.

 

I guess either way there would need to be some mod to accommodate the e.g. different microphone technology.

It'd be no problem to make sure we could supply phantom power/bias voltage for electret mics.

[boatman]

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I guess either way there would need to be some mod to accommodate the e.g. different microphone technology.

It'd be no problem to make sure we could supply phantom power/bias voltage for electret mics.

 

Electret mics have a higher output than dynamic so it would need a switch to both add the bias and reduce the mic amp gain.

 

Which bridge amp chip are you thinking of using?

TPA3122 looks good. Class D, £1.53 in small quantities, 24v rail no problem.

 

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Yes, that one looks good. It's a pity about the size of the package but I guess that's the reason for the larger PCB.

[DanSteely]

Hi All,

 

I've just had the following PCB quote back:

 

 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Dear Sir if you go to www.pcbpanel.co.uk you can Order PanelD at £50.00 + VAT

 

This will give you 10 Circuits the standard delivery is 5days and there is a charge for delivery of £7.65 + VAT total cost £69.18. thisall comes next day by special post.

 

You would need to send 274-x Gerber's or an aperture list if possible along with the NC Drill files.

 

Regards Clive Richards

 

DIAL ART (P.C.) LIMITED, 3 AIRFIELD WAY, CHRISTCHURCH, DORSET, BH23 3PE

TEL: 01202 486486

FAX: 01202 488988

E-MAIL: pcbsales@dialart.com

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

 

Again, echoing the problems the Chinese manufactures (& BR members) have identified : The Gerber files cannot be used as is..

[pmiller056]

Hi

 

It may be difficult to use PC type headphone and microphone sets where there is a common connection to one side of the speaker and microphone (cable screen). My experience with TecPro type systems is that the speaker and microphone require separate earth/ground/common connections. Trying to common them will make the system unstable and prone to ringing and self oscillation. I know the circuit diagram shows speaker ground and microphone ground going to the same node... If someone does design a new PCB, then with very careful layout and a reasonably complete groundplane it should be possible to make a system stable with a common speaker and microphone connection.

 

Regards

 

Peter

[timsabre]

It may be difficult to use PC type headphone and microphone sets where there is a common connection to one side of the speaker and microphone (cable screen).

I used a cheap headset like this and it isn't a problem, however having 3.5mm jacks on a beltpack is a bit of a liability, they are rubbish connectors and very prone to getting bent/damaged/pulled out unexpectedly.

 

Changing the plugs to XLR is also a nightmare because they always seem to use tinsel-type cable or enamelled cable which is just about impossible to solder.

[cedd]

I had a pretty good stab at getting comclone working a few years ago. I never succeeded but if I'm honest I've never been that good at component-based electronics. I'm very much a systems and relays kind of guy!

 

Anyway, if anybody out there can get a working pcb, with a list of parts easily sourced from UK suppliers, I'd probably be interested in buying a few pcb's. I'd maybe be interested in 10, but I'd kind of need to know that somebody had got the things working first. My main problem last time was that I was struggling to source the parts off of his components list as they were American suppliers and I struggled to find UK equivalents. But as my first comment says, this isn't my forte, though my soldering's pretty good. Perhaps I was just looking in the wrong places or for the wrong things!

[smalljoshua]

I'm in the same boat, I'd likely buy 5-10 of the things if it was proven working.

 

Maybe we should get a pot going on kickstarter?

 

Josh

[NeilVP]

My circuit theory (& simulations) tell me that the R26= 33R in the left hand circuit and R27=22R in the RH circuit are superflous. They neither help nor hinder.

 

I design PCBs for a living so could easily generate the necessary files from either re-drawing the circuit diagram or from a schematic in either Altium, PADS Logic or DxDesigner. I can make it all with leaded components (as opposed to surface mount) so "anyone" could assemble it complete with a Bill Of Materials giving manufacturer part numbers and order codes from the likes of Farnell, cpc or RS. Getting a dozen boards made will not be cost effective so there would have to be a demand for say 30 to make it worthwhile. The more that are required the less they will cost. So if people would like to indicate how many thany would like, if we get to 30, I'll get on with it.

 

Neil

 

 

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It is correct and does work like that, I have built it.

Click here to download my working circuit diagram as pdf - I think it's pretty much the same as the original.

 

 

I've just read that the ComClone is a copy of a Clearcom MR-102, and a quick butchers at the schematic shows a similar arrangement around the final opamp for headphone drive, albeit using 22R rather than 33R.

 

MR-102a manual which includes schematgic here (PDF, 320KB).

 

A close look at the output stages for Comclone and the MR102 show that the Comclone circuit is indeed incorrect. The positive feedback resistor R26 in the Comclone circuit should be connected to the junction of R27 & C22 and not directly to pin 7 of U3. I hope that helps anyone who is thinking of trying to make it work.

 

http://www.mydesk.myzen.co.uk/_Useful/OutputStages.jpg

 

I'm in the same boat, I'd likely buy 5-10 of the things if it was proven working.

 

Maybe we should get a pot going on kickstarter?

 

Josh

[Brian]

My circuit theory (& simulations) tell me that the R26= 33R in the left hand circuit and R27=22R in the RH circuit are superflous. They neither help nor hinder.

As we've already ascertained, the original ComClone has an error in that part of the schematic. However, the 22R in the Clearcom schematic is most definitely required.

[DanSteely]

I was unaware of the Kickstarter joint funding method suggested by Josh and, but, with everyone's agreement, would deposit some funds to e.g. get some boards made (10 in my case)..

(The quote I cited above was £70.00 for 10x (ComClone) boards inc VAT & delivery. I have never dealt with a PCB manufacturer before but assume that prices will fall as volumes go up..)

 

I'd equally be happy to deposit some funds via BACS or PayPal to a member who wanted to place a bulk order for PCB's.

 

Whatever works logically, transparently and gets consensus, I'm up for...

 

BTW: I'm possibly jumping the gun here and don't mean to pressure anyone...

[pmiller056]

Hi

 

Jack plugs and sockets (particularly the 3.5mm flavour because they are generally junk) have no place in a stage or theatre environment because they wear badly and I'm sure we all have suffered shows compromised by them in one way or another. Changing 3.5mm jacks to XLR's will be worth the effort and expense in the long run. A quick rummage of suppliers websites suggests that there are plenty of cheap headphones available with separated speaker and microphone connections (but 3.5mm jack plugs :-( )

 

I've found the best way to solder Tinsel/Enamelled wire is with a clean, really hot soldering iron. The heat will quickly burn away any polyurethane enamel or nylon tinsel reinforcment. Note that the fumes are unpleasant! The soldered connection will need to be well supported by any strain relief system because it tends to be very brittle.

 

Any suggestions for a power supply? I'm thinking of a 'brick in the wall' or 'wall wart' type power supply, given that they are robust and fault tolerant if you get a reasonable quality one. Most of them are double insulated with a floating (non-earthed) output - will this be a problem or will I be better trying to find (a more expensive) one with an earthed output?

 

Peter

[timsabre]

 

Any suggestions for a power supply? I'm thinking of a 'brick in the wall' or 'wall wart' type power supply, given that they are robust and fault tolerant if you get a reasonable quality one. Most of them are double insulated with a floating (non-earthed) output - will this be a problem or will I be better trying to find (a more expensive) one with an earthed output?

 

My comclone system just uses a 24V switch-mode type wall wart, change the connector to XLR socket and fit the line termination components in the socket.

It's important to use a switch mode type supply rather than a transformer one because the switch mode ones usually have good overload/short circuit protection, the transformer ones often don't (and may not be well regulated either).

[pdherring]

I would certainly be interested in 5-10 if the price was as good as being discussed. Does anyone have any idea of reasonably priced headphones to use that are similar to the normal single muff items we all use with the Tecpro etc gear.

[Paul TC]

I would certainly be interested in 5-10 if the price was as good as being discussed. Does anyone have any idea of reasonably priced headphones to use that are similar to the normal single muff items we all use with the Tecpro etc gear.

If the "BlueClone" can be made to support PC style headsets with electret mics & 32 ohm earpieces, then there is a range of headsets, dual and single ear at under £15 each. ( or from the 99p store @99p :) ).