Waddycall

You might want to bear in the mind that the headphone out on the evo2 (800 at least possibly 500) can be irritatingly noisy. You might want to check through this thread and see what others say. Also the line in is a mono line in not stereo aux in so if you want to play along with tracks in your headphones they’ll be mono.

Just ring their main number and press the option for service. It just sounds a bit more complicated as everyone name drops the great Dave Green.

I sold a rumble 115 cab on here recently and sent it via parcelforce. I dropped it off at our local post office. I went a bit overboard on the packaging but would rather do that than have it arrived damaged. I put a layer of thick cardboard over the grill with 3 lengths of 2 x 1 timber taped to it as reinforcement bars across the speaker grille then put a layer of bubble wrap over the whole thing and then a layer of cardboard and lots and lots of tape. Worked a treat but took me hours!

If speaking to Dave Green at Ashdown sounds daunting it’s not. Just ring their number and choose ‘service’ and you’ll probably get Dave. He’s very helpful.

Yuk

Thanks for the heads up on these Rich. Just got one from eBay for £41 👍😀 (plus shipping). Sounds ace.

Haha ha well hopefully I’ve learnt something - bridged = 1 input through both channels to 1 output effectively operates as 1 amp paralellel = 1 input, through two independant channels to two independant outputs effectively two amps with the same input.

I’m experimenting with giving up on bass specific amps and got a class a/b power amp to try with my bass pod. I feel very optimistic about it. No band practice til next Thursday so fingers crossed it’s going to do what I think it will.

Thanks Phil, it all makes sense. I understand ohms law but some posts have led me to believe that its more complicated than that. I was also unsure if there was additional risks from bridging caused by some kind of phase shifting or something else I might make up but if volts are volts bridged or not then its all good with me. i enjoy tinkering with gear, experimenting with tone and like to understand the technical aspects hence the original post👍

Right, thanks folks - that wraps it up for me. Also had a look at a few more class d heads. Fender rumbles are also bridged at least the 150, 350 and 800 are. If I’m looking for a power amp again in the future (which I may be) I’d be tempted to go small and put it in bridge mode. No point in paying for and carrying twice as much amp as you need.

Yeah but 🤣

Ace - I’ll go with that until someone comes along and appears to contradict it! No mental torture here just genuine interest 🤪 just seems to be an automatic “don’t put it in bridge mode” response to power amp stuff which I’m curious about especially as it seems some amps are supplied in bridge mode from the factory.

Thanks Bill. This is good stuff. I appreciate everyone’s comments on this but I’m still a bit confused. Maybe that’s because I’m going round in circles due to thinking about watts/power. So a given cab at a given frequency can handle a certain amount of voltage swing before it suffers mechanical damage? Is it feasible then that the two theoretical (one bridged one single channel) 300w rated amps (however iffy the rating may be) could be able to put the same voltage swing onto the same cab? What I think I’m struggling with is the difference between a voltage swing of equal magnitude/amplitude from a single channel amp and a bridged amp. Does that make sense? i.e, is voltage swing voltage swing or can it have different characteristics dependant on single channel or bridge mode? im assuming higher power amps can generally put a higher voltage swing into a given load?

Yes. You're not considering impedance. What if had said 300w into 8ohms? Am I still missing something relating to impedance?

That would suggest that if I wanted a an amp at say 300w (to move away slightly from the power concern issues) theres no difference between buying a single channel amp rated at 300w or buying a small two channel amp and bridging it to get the equivalent 300w which seems contradictory to the posts regarding voltage swing or am I missing the point? That would also suggest that anyone using one channel of a two channel power amp would have been better off getting a low power one and bridging it to get the same output.

And what does that mean to users of class d amps like the Ashdown RM that are bridged as standard? Are they more likely to blow speakers than users of single channel analogue amps of the same power rating?

Sorry what I should have said is that it sounds like there is a difference between using one channel of an amp that gives 800 W per channel and using both channels of a smaller amp bridged at 800 W.

Ace. So it’s basically the combined push pull on the driver? And there is a difference between 800w bridged and 800w un-bridged.

Cool, so this is getting interesting! What’s the difference between power and voltage swing? Is it due to the fact that it’s not a simple dc voltage at a steady current?

Thanks, the bridge mode or not makes no difference makes sense. Something else I can’t get my head round- power amp manufacturers seem to recommend choosing an amp that’s twice the rated power of the cabs. I guess that makes sense for a fixed venue type installation but if I followed that advice I’d be connecting a 2.4kw amp to my 210! apparently I also need clean headroom - how much is that? I need to avoid clipping the amp as that will damage the cab but don’t want so much power I risk overpowering the cab. Where’s the balance? by the way I’m not having any issues - just curious. My old Hartke Ha350 (250w into my cab) is plenty loud enough - my power amp is bridged to compensate for low input voltage. I’ve no intention of blowing anything up or deafening myself.

Recent threads including one about my new power amp have got me curious about bridge mode and it’s perils. I can understand the potential risk of having too much power but get an impression that it’s that power specifically delivered in bridge mode that can cause problems. Is this the case or is it as simple as too much power is bad, bridge mode or otherwise? Also my old Ashdown RM800 evo II operated permanently in bridge mode with no indication of this other than in the manual (I think). Is it common for class d bass heads to run permanently in bridge mode (I think all the rm evos do) If so are cabs connected to these amps at more risk than those connected to other amps of similar power? my new power amp puts 830w into 4ohm. My old RM head puts 800w into 4 ohms. My 8 ohm cab has a continuous power rating of 1200w. Other than the extra 30w is the power amp more likely to damage my cab than the RM? id appreciate any comments in thicko speak.

Yep, all tweaked. I believe I’ve got it as good as I can get it without clipping and I’ve evened out the level of all the patches I’m using. The factory presets are a nightmare for differing levels!

Here’s what the manual has to say about the gain controls -