Help setting up a rig with Ashdown CTM 100

[Kateplaysbass]

This is probably a very basic question, apologies, but my knowledge of matching heads and cabs is limited, and I'm paranoid about damaging my lovely new tube head!

 

So, I've just acquired an Ashdown CTM 100, courtesy of a fellow Basschatter. At the moment, I've just got it set up with a LB 212 cab, which is 300w at 4ohm impedance. That's more than sufficient for home use.

 

However, I would potentially like to gig with this amp, in which case I'm thinking a single cab may not be enough to compete with an enthusiastic drummer! I also have an Ashdown VS 115 cab, which I had listed for sale, but now I'm wondering if I should keep it to use in a rig with this head, with the two cabs stacked horizontally.

 

This is where the technical side of things starts to exceed my knowledge. The head has outputs at 2 ohms, 4 ohms and 8 ohms, but only one socket for each. The LB 212 is 300w at 4 ohms and the VS 115 is 300w at 8 ohms. Both cabs have 2 sockets.

 

Is there a way I can make this rig work? Is it as simple as connecting the 4 ohm output socket to the LB 212 and the 8 ohm output socket to the VS 115 - or will that result in a fire?! Or alternatively can I use the 2 ohm output with some kind of special cable/ adaptor that allows me to connect both cabs in parallel? 

 

Please be gentle if this is a very stupid set of questions! 

[Reggaebass]

1 hour ago, Kateplaysbass said:

Is it as simple as connecting the 4 ohm output socket to the LB 212 and the 8 ohm output socket to the VS 115

Hi, fairly sure you can’t use both outlets at the same time on a valve amp as I asked this once myself , but I’m sure someone with more expertise will be along soon 

[PinkMohawk]

It's not ideal, really. My recommendation is to get shot of the 15 and pick up another 4 ohm cab. With two 4 ohm cabs, you'd be running them in series rather than parallel, all that means is that you'd go: 8ohm output - cab 1 - cab 2. The reason there's two speakons on the back of the cabs is so that you can use one as a passthrough to the next cab. Of course, you could always just buy my Ashdown 8x10 off of me...

[Kateplaysbass]

1 minute ago, PinkMohawk said:

It's not ideal, really. My recommendation is to get shot of the 15 and pick up another 4 ohm cab. With two 4 ohm cabs, you'd be running them in series rather than parallel, all that means is that you'd go: 8ohm output - cab 1 - cab 2. The reason there's two speakons on the back of the cabs is so that you can use one as a passthrough to the next cab. Of course, you could always just buy my Ashdown 8x10 off of me...

I thought that might end up being the answer! But even in my wildest dreams I'm not going to justify having an 8x10!! 

[PinkMohawk]

8 minutes ago, Kateplaysbass said:

I thought that might end up being the answer! But even in my wildest dreams I'm not going to justify having an 8x10!! 

Ahh one day someone will take the bloody thing off my hands. But yeah, having two 2x12's would be plenty for most bands regardless of how enthusiastic the drummer is. Always annoyed me how they don't just label one of the speakons as a 'thru' and just leave them blank instead. 

[ossyrocks]

17 minutes ago, PinkMohawk said:

It's not ideal, really. My recommendation is to get shot of the 15 and pick up another 4 ohm cab. With two 4 ohm cabs, you'd be running them in series rather than parallel, all that means is that you'd go: 8ohm output - cab 1 - cab 2. The reason there's two speakons on the back of the cabs is so that you can use one as a passthrough to the next cab. Of course, you could always just buy my Ashdown 8x10 off of me...

 

I don't think I agree. And this is quite important.

 

Most cabs with two speakon connectors are wired to run the cabs in parallel, not series. I would bet money the Ashdown cab is wired this way. Connecting another cab to the Ashdown cab would present a total load to the amp of 2 ohms, not 8 ohms.

 

Rob

 

 

Edited April 13 by ossyrocks

[PinkMohawk]

 

1 minute ago, ossyrocks said:

 

I don't think I agree. And this is quite important.

 

Most cabs with two speakon connectors are wired to run the cabs in parallel, not series. I would bet money the Ashdown cab is wired this way. Connecting another cab to the Ashodown cab would present a total load to the amp of 2 ohms, not 8 ohms.

 

 

Yep, you're absolutely right, that's a brainfart on my part, I've not had to do the cab link thing for a while now. Don't know why I assumed it'd be a series not parallel wiring to both cab jacks. 

[ossyrocks]

Ok. @Kateplaysbass

 

Use only one output from the amp which will match the total load of the cab(s). 

 

If you're just using one cab (LB212), then it's obvious, connect it to the 4 ohm output.

 

If you're using two cabs, both of which are 4 ohms, then the total load will now be 2 ohms, so connect the first cab to that output, and the second cab to the first cab.

 

I really think that the one LB212 would be enough for most situations though, it's worth trying.

 

Rob

[Merton]

What @ossyrocks said ☝🏻

 

I had almost exactly that rig (CTM100 and VS212) and it was plenty for gigs, assuming they weren’t massive or you had PA support if they were.

[Kateplaysbass]

Thanks everyone for the advice. I don't know why I'd assumed that the 212 on its own wouldn't be enough, but that's definitely the easiest solution, so I'll give it a go at our next practice. We don't usually play gigs with PA support.....but they aren't massive either! 

 

 

[BassmanPaul]

I would be a little concerned with the low power of the amplifier. I feel that you would need a cabinet with high sensitivity to avoid running out of head room too early.

Edited April 13 by BassmanPaul

[Frank Blank]

Basschat does exactly what it says on the tin, there.

 

Problem solved - no horse s***.

 

Textbook.

[BassmanPaul]

2 minutes ago, Frank Blank said:

Basschat does exactly what it says on the tin, there.

 

Problem solved - no horse s***.

 

Textbook.

 

?

[Frank Blank]

4 minutes ago, BassmanPaul said:

?

 

I was expressing joy at Basschatters helping out a fellow Basschatter with a problem, the forum doing it's thing.

[Merton]

27 minutes ago, BassmanPaul said:

I would be a little concerned with the low power of the amplifier. I feel that you would need a cabinet with high sensitivity to avoid running out of head room too early.

Thankfully the VS212 (and I presume the LB212) was super efficient.

[Kateplaysbass]

Actually, whilst I have all you knowledgeable folk assembled, can I ask a follow up question? 

 

I'm puzzled by the speaker outputs on the CTM 100. They look like 1/4 jacks to me, and that's what the Ashdown website says they are. However it says on the rear panel 'Use Neutrik touchproof connectors only'. This is confusing me. I know Neutrik usually equals Speakon, but these don't look like Speakon sockets. The CTM 300 says 'use Speakon connectors only' so I presume Ashdown are intentionally drawing a distinction, but I've googled 'Neutrik touchproof connectors' and not got much back.

 

It works with a standard 1/4 jack speaker cable, but I don't want to continue using that if it's liable to damage either me or the amp! I don't currently possess any Speakon cables, so I can't just try one out. 

 

Can anyone advise what cable I should be using? 

[ossyrocks]

13 minutes ago, Kateplaysbass said:

Actually, whilst I have all you knowledgeable folk assembled, can I ask a follow up question? 

 

I'm puzzled by the speaker outputs on the CTM 100. They look like 1/4 jacks to me, and that's what the Ashdown website says they are. However it says on the rear panel 'Use Neutrik touchproof connectors only'. This is confusing me. I know Neutrik usually equals Speakon, but these don't look like Speakon sockets. The CTM 300 says 'use Speakon connectors only' so I presume Ashdown are intentionally drawing a distinction, but I've googled 'Neutrik touchproof connectors' and not got much back.

 

It works with a standard 1/4 jack speaker cable, but I don't want to continue using that if it's liable to damage either me or the amp! I don't currently possess any Speakon cables, so I can't just try one out. 

 

Can anyone advise what cable I should be using? 

I run a vintage valve head into a modern speaker cab on occasion, in a very similar way to what you'll be doing. You just need a good quality mono 1/4" jack to speakon cable. I have these and they do the job. I always carry spares of everything, but that's just me. If you've got it, disaster never happens, when you don't, it does.

 

https://www.designacable.com/van-damme-2x1-5mm-speakon-to-mono-jack-passive-speaker-lead-1.html

 

Rob

[BassmanPaul]

For a 100W amp 1/4" Phone jacks will work fine. It's when the power levels go up the problems arise especially with Solid State amps. As you insert this plugs a momentary short occurs across the speaker jack. This can damage such an amplifier. If you have a choice ALWAYS use Neutrk branded Speakon connectors as the Far East versions can damage the socket.

 

For amps with higher power the 1/4" Phone plugs are not up to the task. They were originally designed for Telephone Switch Boards running at 48V DC at a few hundred milliamps.

 

[Bolo]

Neutrik is a brand of industry professional quality connectors. They make many types among which Jack and Speakon. 

Edited April 14 by Bolo

[Downunderwonder]

Always hook up the speaker before powering up the amp.

 

Always power down before unhooking the cab.

 

Having this as your routine is to prevent an occurence of amp on with no speaker attached = death to amp.

[Lozz196]

Definitely, I don’t even connect the power lead until the speaker lead is connected.

[pete.young]

16 hours ago, Kateplaysbass said:

Actually, whilst I have all you knowledgeable folk assembled, can I ask a follow up question? 

 

I'm puzzled by the speaker outputs on the CTM 100. They look like 1/4 jacks to me, and that's what the Ashdown website says they are. However it says on the rear panel 'Use Neutrik touchproof connectors only'. This is confusing me. I know Neutrik usually equals Speakon, but these don't look like Speakon sockets. The CTM 300 says 'use Speakon connectors only' so I presume Ashdown are intentionally drawing a distinction, but I've googled 'Neutrik touchproof connectors' and not got much back.

 

It works with a standard 1/4 jack speaker cable, but I don't want to continue using that if it's liable to damage either me or the amp! I don't currently possess any Speakon cables, so I can't just try one out. 

 

Can anyone advise what cable I should be using? 

 

I use something like this: https://www.studiospares.com/pro-neutrik-killer-watt-speaker-lead-speakon-to-mono-1-4-inch-jack-1m-25m.htm

 

This design of 1/4 jack plug is more robust and allows the use of greater diameter cable.

 

I think that the explanation for this might be that Ashdown has used the decals made for the CTM300 (which does have Neutrik) on the CTM100,. Maybe they ran out, or didn't bother printing separate decals for the CTM100.

 

If you daisy-chain your VB115 with this cab, you're presenting an overall load of about 2.6 Ohms. 2/3 of the power will go to the VB115 and only 1/3 to the LB212. If you want to move more air, i'd say your best bet is to sell the VB115 and buy another LB212.

[Kateplaysbass]

Thanks again everyone - I love how helpful this forum is. I now have some Speakon cables on their way - thanks for the recommendations - and I feel slightly more knowledgeable. I'll report back on how the LB212 fares against our drummer in due course!