Amp Internals 2

Not sure if this was posted before, Thomann T.amp E4-250.

16kG Class AB amplifier, rated at 4x250W at 8R, 4x400W at 4R.

3x DYP1521 /DYN1521 output devices per channel, no datasheet to be found of these.

2x59V out from the Xformer, 1x 6800uF 100V per half rail, each module (Ch1+2 and Ch3+4) has its own bridge rectifier and set of caps. Both rectifiers are fed from the same Xformer winding though.

The logical way to connect this amp would thus be to have for example Low/High/Low/High and not Low/Low/High/High to spread the power draw.

Tested under load, 1 channel loaded, it does ~52V at 8R and 48.5V at 4R (constant sine wave input @100HZ) which is well over its rated power. I haven't tested all 4 outputs simultaneously.

The clip limiter works as expected and doesn't reduce the output voltage capability, the indicator light comes on at the exact right moment.

Low noise and/or hiss from the outputs with the input potentiometer fully open, barely audible connected to a horn mounted compression driver, ear to horn.

Overall construction looks well though out, the massive downside is the fans, they are loud. 

The fan is some chinesium brand "Tonon TD8025HS" 24VDC brushless fan i can't find much data on. I don't have a tachometer but measured around 303Hz and with 7 blades, it's a 2600rpm fan which draws around 75mA at ~25V, so rather low power fan. With both fans connected and the top cover in place, the amp does around 40ish dB(A) at 1m, very loud.

I just received 2 sunon MF80252V31000UA99 fans with vapo bearing which should be a lot quiter, just need some JST connectors and crimps to connect them.

Unlike stated here: http://https://www.musiker-board.de/threads/the-t-amp-e4-250-seltsame-speakon-belegung.703330/ Thomann seem to have fixed this as the speakons are all wired as expected, CH1&3 have both their channels connected on 1+/- and CH2&4 on 2+/-. Ch2&4 only have 1+/- wired as normal.

The Flir thermal camera spots no significant hotspots to worry about while idle. The section around the bias circuit which is all SMD gets around 50C, and the LM317 linear regs which provide linear supplies in the input circuit are heatshink mounted and get ~55C. Additionally there is a mains input relay near the input connector, which is SanYou SMIH series relay, which has all the appropriate TUV/UL/VDE approvals does get a rather too hot for my liking, it's idling around 55C as well...

I think we bought from the same studio :

Just picked up a pair of Inter-M PA6348 mono blocks. Very substantial beasts with massive heatsink and an interesting layout. There is an option for 24vdc input for running on batteries and the outputs are transformer coupled. They weight a ton though, 23 kg a piece for "only" 480W output.