Basschat 1x12 Active FRFR Cabinet

[Dood 963]

I appreciate it's another expense, but for those who really want to angle the cabinet further upwards, a flip out kick stand as an added option? 

[TheGreek 2,843]

Proof of the pudding...

Can we try one at the next SE Bash??? 🤤🤤

[Chienmortbb 135]

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18 hours ago, Dood said:

I appreciate it's another expense, but for those who really want to angle the cabinet further upwards, a flip out kick stand as an added option? 

The orientation of the horn has been designed tso that you can hear yourself with the cab vertical. Unless you need to use it as a floor monitor you should be OK. Hopefully Stevie can elaborate.

[Chienmortbb 135]

On 05/05/2019 at 20:10, TheGreek said:

Proof of the pudding...

Can we try one at the next SE Bash??? 🤤🤤

Depends when it isand how well I get on with the design.

It is October so should be OK.

Edited May 7 by Chienmortbb

[Chienmortbb 135]

Neutrik have kindly sent some airtight connectors to help with the project. The current idea is to put the mains input and Speakon out on the back but all the signal in/outs on the front or top front. Neutrik have supplied some of their new Powercon connectors but we will still need a fuse, an indicator and possibly a switch. The powercon’s are safe to remove while the unit is powered and do not really need a switch. So the question is, do we just need a mute switch rather than a power switch or is a power switch needed? 

I looked at my current MK2 cab and it is not easy to modify a built cabinet so I am going to use the flat pack when. It comes. I will build and test the circuits outside the cabinet initially and fit the modules into the flat pack when it comes. 

I checked the output of the Zoom Multi effects units and they are unbalanced but still output 0dBu ( 0.775V) the same as a Helix. So the jack input will be switchable between line  and Instrument. 

[Brook_fan 141]

A bit late to the party on this project.  Anyone know what sort of price range we would be talking about?  And would it work with an acoustic bass guitar with a headway eb2 preamp as the front end?

Robbie

[Happy Jack 2,012]

And more to the point, what sort of handles will it have. 

[converse320 32]

Curious as to the choice of Class D for this project, given the difficulties of maintenance and repair if anything goes wrong.   I've had a home made FRFR powered cab going for nearly 30 years, amp of which is basically half of a Naim 250 with a mic level, guitar level and line level inputs.   Its been completely bomb proof and sounds fantastic.

[spyder 27]

15 hours ago, converse320 said:

Curious as to the choice of Class D for this project, given the difficulties of maintenance and repair if anything goes wrong.   I've had a home made FRFR powered cab going for nearly 30 years, amp of which is basically half of a Naim 250 with a mic level, guitar level and line level inputs.   Its been completely bomb proof and sounds fantastic.

Naim hifi amps are built to a very high standard. They can be serviced easy enough and have amazing sound quality. Unfortunately the new cost of the stereo 250 is over £3000. Best to use class D. 

[converse320 32]

13 hours ago, spyder said:

Naim hifi amps are built to a very high standard. They can be serviced easy enough and have amazing sound quality. Unfortunately the new cost of the stereo 250 is over £3000. Best to use class D. 

 

13 hours ago, spyder said:

Naim hifi amps are built to a very high standard. They can be serviced easy enough and have amazing sound quality. Unfortunately the new cost of the stereo 250 is over £3000. Best to use class D. 

I wasn't meaning to cut up a a real 250!   Naim used a published circuit and decent clone mono were PCBs available at one time.  

[Mottlefeeder 66]

On 09/05/2019 at 19:58, Chienmortbb said:

... but we will still need a fuse, an indicator and possibly a switch. The powercon’s are safe to remove while the unit is powered and do not really need a switch. So the question is, do we just need a mute switch rather than a power switch or is a power switch needed...

If it should ever fail with a spectacular puff of smoke, the lack of a power switch might be regretted. That will also be the day it is so close to something else that you cannot easily disconnect the power lead.

I would also suggest that you should be able to power down when you are having a break between sets.

David

Edited May 16 by Mottlefeeder

[Jack 271]

On 09/05/2019 at 19:58, Chienmortbb said:

 The current idea is to put the mains input and Speakon out on the back but all the signal in/outs on the front or top front.

That makes sense of they're only ever going to be used as backline and one at a time. I would want to stack them or run them as speaker on sick pa systems though. If I'm the only one then fair enough, but if there's enough interest from others could we consider having everything on the back?

[spyder 27]

This sounds real interesting.

Ive just bought a Head Rush Gigboard and would love to try a FRFR instead of my usual amp and cab.

 

Edited May 22 by spyder

[CameronJ 1,072]

3 minutes ago, spyder said:

This sounds real interesting.

Ive just bought a Head Rush Gigboard and would love to try a FRFR instead of my usual amp and cab.

 

How is the Gigboard for bass? I’ve got a Line 6 HX Stomp myself but have been intrigued by the Headrush stuff too.

[Al Krow 2,188]

55 minutes ago, spyder said:

This sounds real interesting.

I've just bought a Head Rush Gigboard and would love to try a FRFR instead of my usual amp and cab.

51 minutes ago, CameronJ said:

How is the Gigboard for bass? I’ve got a Line 6 HX Stomp myself but have been intrigued by the Headrush stuff too.

Oh my...that does look like a nice piece of kit.

Definitely warrants it's own thread Spyder! 

[Chienmortbb 135]

Despite the radio silence, things are progressing. The power module for the prototype will be the 125ASX2 from ICEpower. Why? Because I have one. It is capable of about 270 watts into 8R and that meets the original requirement of the 1x12 cab, keeping up with a heavy handed drummer. 

It can also output close to 500W into 4R. If two cabs are used the acoustic output will be enough to fill almost anywhere.  I will admit that the AS700 module would be my choice but they are much harder to get (unless enough people are interested). 

I am up to my ears in other things at the moment but I now have most of the components to start on the prototype. Watch this space. 

[JPJ 74]

Subscribed, this sounds very interesting.

[nilebodgers 35]

On 13/05/2019 at 23:59, Mottlefeeder said:

If it should ever fail with a spectacular puff of smoke, the lack of a power switch might be regretted. That will also be the day it is so close to something else that you cannot easily disconnect the power lead.

I would also suggest that you should be able to power down when you are having a break between sets.

David

A switch is advisable to be able to safely isolate the unit.

An indicator LED on the thermal monitor pin would also be useful, although how important that is depends whether the module in the cabinet can be thermalled in any likely use. If the module can be force ventilated by the port air movement that would help 👍

One thing that occured to me after a bit of googling - are the Chinese counterfeiting the icepower modules? They appear to be suspicously cheap on ebay compared to a real uk distributor (Profusion).

[Chienmortbb 135]

Hard to tell about the Chinese and fakes. I did  ask Icepower and they say there are fakes out there. However if you buy in quantity from IcePower, you could just about sell at the prices advertised on EBay but your margins would be small. The Profusion prices do seem excessive AND they will only sell IcePower to registered companies. 

I know that Ghent Audio, the Chinese’s maker of cable looms for icepower modules, also sells complete amps and has, on occasion, sold excess modules. Of course it may be the case that some ICEPower modules slip out the back door of some far eastern factory without ICEPower’s knowledge. 

Profusion do not even list the price of the 700AS1 module as it is more restricted than the ASX range. However it is a fine module and has been used by a number of manufactures. It is also on my good friend passinwind’s home brew Bass amp. 

As for the over temp indication, that is easy. I don’t envisage a problem with heat as the inside of the cabinet is a large volume and the size of the port should allow some airflow with the outside world.  Although the driver will dissipate heat, I expect that under normal conditions the cabinet will not get too hot. If it does then a sealed plate amp type design would be needed. 

 

[Chienmortbb 135]

I have been awaiting some parts and the majority arrived today.

As I have said before the preamp will be basic. As the design assumes the uses of a digital Multi-Effects unit as the main source,  there is no EQ on board. Even low cost units such as Zoom B1 Four have easily accessible EQ  so it would be a waste to fit more. Passive EQ reduces the signal level and active EQ is more complex. Both will increase the noise of the preamp (what electronic engineers call noise, we hear as hiss).

I  am using Elliott Sound Products printed circuit boards .There are three PCBs. The first is a power supply board Project 05. This will take the +/- 23V auxiliary rails from the Icepower module. 

Edited June 25 by Chienmortbb

[Chienmortbb 135]

If you can get the 700AS1 module, the auxiliary outputs are already +\- 15V and the preamp power supply is not required.

PCB 87A contains the circuits for two balanced line recievers. One will be used as desinged by Rod and the other will be modified as an instrument level input simiklar to that shown in the ESP Project 27.

The outputs will be mixed and sent to both the line transmitters on the Project 87B PCB. The output of one will be fed to the two amplifiers in the ICEpower 125ASX2 power amplifier module this will "bridge" the amplifier giving about 450 Watts into 4 ohms but in excess of 270 watts into 8 ohms. This would give the meet original Baschat 1x12  spec of giving 120dB output  to keep up with a noist drummer. .

The preamp will be housed in a hammond 1590XX diecast aluminium enclosure the PCBs can be seen above here mounted to the lid of the enclosure. the connectors and controls will be mounted to the base of the enclosure. Now to stare loading (or stuffing as our friends across the pond say) the PCBs. starting with the power supply.

 

Edited June 25 by Chienmortbb

[Chienmortbb 135]

I have finished soldering the parts to the power supply board. Next on to the Input board. 

The PCB shown below has a space for a bridge rectifier and another large electrolytic capacitor on each rail but they are not needed with the ICEPower module’s dc aux power  outputs. As there is more space,I have laid the caps down and fixed them with cable ties. I had to drill the holes for the cable ties but there was plenty of space on the PCB. Remember that this PCB is not needed with the 700AS1 module, only the 125ASX2 or even 250ASX2. 

 

Edited June 25 by Chienmortbb

[LukeFRC 444]

What are you building it onto? 

[Chienmortbb 135]

That is the lid of a die cast aluminium box. The connectors and controls will be mounted on the base of the box. I did it this way as the base is flatter than the lid and so easier to get a good seal. 

[Chienmortbb 135]

The best laid plans.., I ordered some connectors  for the two smaller boards but stupidly ordered the wrong pitch. Of course I would have needed a crimp tool  too and in the end I decided to use some PCB  terminal blocks. They are on order along with some 30mm hex standoffs. The wrong connectors will go on EBay.

The standoffs are to mount the power amp module on to an aluminium sheet to add extra heat sinking. Pictures to follow. 

The input board is now populated and soldered. Just output board to populate and solder the output board.  

Edited July 6 by Chienmortbb