Ruby amp pin 1 and 8 out

[heatsink]

Hi

Just wondering if anyone has any ideas about increasing the clean volume of my ruby amp. I wanted to have a clean sound only and have left pins 1 and 8 of the lm386 ic out of the circuit and it's great except it would be nice to increase the volume a little.  Any advice appreciated.
Thanks
Peter

[ambulancevoice]

thou could use a 12v power supply instead of 9v
thou could put a 1k trim pot bettween pins 1 and 8, set the vol max, and slowly turn the trimpot till the point just before it starts to drive, thats the max clean vol
ummm... bigger speaker??

[brett]

Big, efficient speakers really helps.  Try a 4x12 cab.  You'll be amazed.
Also, I've tried 386s at higher voltages, and they don't usually die until about 18 V. 15 V gives about 4 W clean (9 V gives 1/2 W).  Heatsink or fan very well !!

[ambulancevoice]

if your gonna run this thing at 15 volts, make sure your lm386 is the 15v-18v version, and not the 9v-12v version!!

[heatsink]

Thanks very much for the info. I am running from a 9 volt battery at the moment into a single 12 eminance speaker (8ohms). I happen to have a 5k trim pot here so i will play around with that. Does it work like the more resistance on the line then the gain increases?
Cheers

[FisTheGoon]

I did what u did by leaving the pin 1 and 8 out.What i got from the speaker was so low in vol. then i just put  jumper on  pin 1 and 8.It sound louder.  I been using lot of speaker for this ruby but it seem a guitar speaker is the best for it.It sound big when i use peavey rage 158 guitar speaker with the 3.2ohms.It really amazed me how loud this ruby can make with just 9v battery.

[petemoore]

  9v is ~small V to work with as PS, 12v opens things up a touch.
  I have a 10uf cap across/open...just kinda 1/2 hangin' exactly right so I can hook it to pin 8 to increase gain.
  2 x LM386 is another possible option:
  http://runoffgroove.com/littlegem.html
  Speaker choice..too big and heavy, the amp won't power it right, light cone/effecient types are good, too small and the speaker limits/distorts, ohmage of course should be observed...lower ohmage gets more current/volume, and heats or fries the chip at some point, add more heat sink..or reduce current..or fried chip.
 
 
   

[Krinor]

12 Volts and the Bassman mod. has so far proved to be my loudest, cleanest Ruby. Putting an RC filter from pin 1 to 5 improves the overall sound even more (in terms of cleanness), but the volume goes down a bit. If you use a 12" speaker you'll still end up with a great amp for practice and maybe even for recording. With these mods the amp sounds very nice with phasers, filters, delays etc.

(Edit: typo)

[ambulancevoice]

a 4 ohm speaker or two 8 ohm speakers in parallel or one 8 ohm and two 16 ohm speakers in parallel (both configurations equal 4 ohms) will get more volume too
also, are you using the national semiconductor lm386?? cause according to Tim Escobedol, the JRC386 is much more stable (aka better) compared the the LM386, maybe this will help some how... or not

[Krinor]

Someone said that the NJM386D was really good. That's the same as the JRC I guess (company namechange).

[petemoore]

a 4 ohm speaker or two 8 ohm speakers in parallel or one 8 ohm and two 16 ohm speakers in parallel
  nothing 'wrong' with it, except the two 16ohmers coils will be sharing the same load as the one 8ohmer is getting.

[Krinor]

Hey, what about going down to 2 ohm ?! (2 x 4" speakers in parallell) Isn't that actually possible with the LM386 if you leave pin 8 open and pin 1 connected to ground via a resistor - and maybe some other small modifications (according to the datasheet)  ? Wouldn't that give more ooomph ? Just a thought.