20 Most Recent Mackie SRM-450 System - Page 3 Questions & Answers

Have you check the inside fuse?

This is caused due to a fragile class d amp design engineering, you should swap for the V1's, waaaay better, hope this helps.

SRM450V1 fuse is located inside amp just where the AC mains connector is, hope it helps.

Power amp failure, it is the model V1 or V2?

You certainly will need at least two units and a stereo mixer or stereo audio source.

Be prepared to buy another instead of sending defective unit for a fix, in fact better to buy another model but NOT the V2...

Some of the +15V/-15V is missing at power supply and this is a good starting point, let me know if i can help you more.

This is a very fragile design, very efficient though but never as reliable as SRM450V1, they did this for lighter weight purposes but definitively would not recommended, almost certainly better to buy the whole amp instead try to fix the thing out because of plenty of distasteful results/smoke will show up in the 85% of the attempts so consider yourself warned, good luck.

Mackie but not the SRM450V2, believe me.

Please let me know your SRM issues to help you out.

Could be 2N4401/2N4403, PN2222A/MPS2907A, NPN/PNP, NTE replacements are NPN/123AP and PNP/159, At radio Shack, Mouser Electronics, Newark Electronics, D'Albani Corporation and a number of places as this is a very common small signal transistors, hope this helps.

Maybe got disconnected from inside the amp, let me know if i can help more.

I've posted for this already.

Dusty/Faulty switch and/or opamp inside pcb, let me know to help more/.

Since this is a bi-amplified speaker there's only 2 possibilities here:*Tweeter amp or,*Tweeter diaphragm.You can test the diaphragm as a starting point using an ohmmeter to verify tweeter coil impedance, let me know if i can help more.

It maybe needs a bias check/re-adjust, previous general diagnosis of power output device parameters.

I need more information, but some similar event i remember with SRM450 and was the paper cone on the speaker, not visible from outside but inside was severely cracked all round, hope this helps.

Generally speaking this is a common issue with SRM-450 and it's due to opamp burned out inside electronic pcb, let me know further to improve help.

Fuse is located inside, just in the AC main connector pcb, very easy to see it, just take apart the amp by unscrewing the plate with a phillips screwdriver, don't pull so hard, as it has a wire connector to hook up amp with speakers, let me know if i can help more.

Yaou will have to take a look at Power Output Stages, Q34/Q35, MJE2955/MJE3055 power output transistors, as well as the other amp with B817/D1047 power devices, first one drives the woofer and the other the hf driver, let me know further.