Rod Elliot 100W amp suggestions?

[janey]

wich output transistor are better for amp.
i am planing to drive 4 ohm load.
2sc2922/2sa1216 or 2SC3281/2SA1302
i need the best sound possible.
is there any tweaks for better sound.
thanks

 

[P.Lacombe]

I do agree with Samuel. 2955/3055 suffers from poor linearity, causing THD, and poor bandwidth, causing TID. This is distinctly audible. I'm surprised that Rod uses this cheap transistors... which can easily ruin entirely a good design.

Regards, P.Lacombe.

 

[bawang]

Toshiba 2SA1302/C3281

To all of you who wishes to use the Toshiba 2SA1302/C3281 pair, please be informed that Toshiba has discontinued these pair and replaced them with a new line, can't remember the exact numbers but you all can check at the Toshiba website.

Also, there's a lot of fake Toshiba transistors being sold especially the 1302/3281 pair!

 

[Geoff]

The new Toshiba devices are 2SA1943 and 2SC5200. Alternatively, use the ONSemi MJL1302A and MJL3281A.

 

[mlloyd1]

If you need TO3 (metal case) vs. TO3P or the other big plastic package, look into the MJ21193 / MJ21194. These do not appear to have the "extended beta" performance to the same extent as the 1302/3281 pairs, but they look good and have a higher PD and SOA - i.e. really rugged devices.

Michael

 

[mlloyd1]

(sorry, I hit send before I finished adding the following to my previous post!)

Also, Doug Self had kind words to say about the matching between the MJ4502 and the MJ802. These are older devices and should be as cheap as the 3055/2955 pair with better overall performance. They are in the TO3 metal case, though.

 

[paulb]

Thanks, I may buy some new transistors and plug 'em in place of the 2955/3055 which are TO-3 metal.

 

[Fossil]

Just curious

Saw that the 2922 is of different dimensions (wider). Does the ESP pcb have space for these type of transistors?

 

[palesha]

How about using single 2SC 3858 & 2SA 1494 in the output for 4 ohms load instead of output dual pair of 2N3055\2N2955 for 100W RMS.
MP

 

[palesha]

If we use the amplifier with the 2N3055\2N2955 just for Subwoofer application will be ok or changing with better devices like 2SC 3858\2SA1494 will make difference.
MP

 

[tiroth]

Re: Just curious

Saw that the 2922 is of different dimensions (wider). Does the ESP pcb have space for these type of transistors?

The ESP board is pretty darn flexible...Rod suggests three different mounting strategies, and then you can always just mount the transistors off-board if you feel like it.

 

[LightHaMMer]

-Off Topic-

But I just wanted to say to you guyz, I've built this amp for a guitar amplifier, designed my own pcb's from the schematics, worked first time and it kicks behind!

I have complete faith in Rod's projects as they allways seem to work 🙂