Hi there, I'm basically an FX pedal builder but lately I developed a lot of preamps ideas so I moved on amps. (well I'm trying to)

So now, I'm kinda stuck in this situation:

I designed a bass preamp, it's an idea of mine from start to finish and I'm very very happy on how it sounds when I try it on the PA of my 400w Ashdown. The whole thing was meant to be placed in a box with a connex Class D module wich doubles also as regulated power supply but, as I play it (even at very low master levels) the board goes into protection and I must restart it.

I contacted Connex and they told me that it goes into protection with every signal bigger than 1.5V RMS and it supports 4V p-p maximum. I know those are the standard values for line-in signal. Bass/guitars preamps anyway are always stronger than this and that's how I minded mine. I've tried to clip my signal with everythin, even with German diodes, but it still seems to much for the Connex.

Is there some kind of rule I'm missing? Or I should buy/build a whole different kind of power amp?


Thank you for any kind of help,

Ciao!

Hi guys! I got this early 80's amp made by LEM
It sounded nice back then but it was too underpowered and running it at max busted the output section so many time years ago, so my mates stopped using it and it got shelved...

I decided to give it another chance but I want to replace the output board with something more efficient..maybe D-class??
I measured the transformer voltage and I got +/-32-35V wich is not that much..

The original has two BDW52C/BDW51C couples and BD317S/BD318S as drivers..

ideas??

it looks like this!

Hi all!

My bass player blown his BassKick 707 twice in this late month. We all know it's a cheap head from the '90s, but we love how it sounds when maxed! It's only 250W, so it's easy to squeeze it to hell. He also push it with a booster and a very hard distortion.

Now, most of all, will jump in to tell me "you don't have to run such a small head so hard", but that's what we did in the last 4 years, touring the whole Italy and Europe with our noise-rock band, so if it lasted so long, why it's so fragile now?

It blows the fuse each time you power it.
So I read that when it happens it's beacause of bad Output Trannies, so I replaced all of them, squeezed new thermal paste and BLING it ran again. (this was the first time). It lasted two days, just in time to record the new album (PHHHEEEW) and then it died again some days ago, during the first rearshall since then.

WTFF???

Useless to say, inside it looks perfect. 

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USUAL STUPID QUESTION

While looking for new heads I saw a nice Peavey bass series 400 from the late '70s. They rate it 210W at 2 ohms, I looked at the back and it has 4+4 output transistors, our Hughes & kettner has only 2+2 (MJ11016/015) and it puts out 250w at 4ohms.
So how the f*uck the peavey is so weaker in comparison?
I suppose it has more modern trannies or something like that, SO my question is:
Is there any way to replace the older trannies in the Peavey with more modern and efficient ones?

Thanks to everyone who'll chime in!

Emanuele.

There must be a simple answer for that. Mixing current feedback on typical BJT amps has been a goal for the whole 90's, then mosfets came and no current feedback at all, I was wondering that also for class D amps..

Mosfet trannies are already sensitive to speaker dampening and stuff??

It's my main amp from years but lately it has become dull and lifeless..I also recorded some months ago thru the mixer output, and I'm pretty sure it's in the preamp.
The overall level when I play straight to the amp is much lower and lifeless, then as I put in a LOT of signal with my stompboxes the overall level is kinda right but it's very raw.
It's kinda hard to describe, it's muffled and the harmonic content is really unpleasant, plus the lows don'thave that "breathe" and fast response..

The rail voltages are fine as I get 15.7V on both

May the problem be in all the small electrolytics? I think they're still the originals, the head is from 1977..are they old enough?

 
Hi, my name is Emanuele and I'm on the way of becoming a full time Solid State player (well I've been that since my first little amp to be honest) since a nice HH IC100L is coming here..I barely can't wait anymore of getting my hands over this baby! In the meanwhile I found this forum so I feel I must sign in being both a player and a DIYer..
Dunno but someone here should have known me as Superfuzz on Offsetguitars.org and as Emanuele on Freestompoxes.org..

Ciao!