18watt vs. 36watt

Double-Bubble! Place for discussing the 36W version...

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Great_King_Rat
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18watt vs. 36watt

Post by Great_King_Rat »

What is the difference between the 2. Is it just more power? Is the tone any different? Do they use them same tone circuit, etc.

Thanks

-gkr
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chris_deveau
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Post by chris_deveau »

Go to the Zounds section and listen to the "Richie's" and "Richamp" clips for a tone comparison. The Richie's is a 18 watt TMB, and the Richamp is a 36 watt, as i recall. Both are Richie/Plexi modded designs with the schematics in the Downloads area..

-chris
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Post by Great_King_Rat »

Thanks for the info, however, I just bought an 18watter TMB which is based on 36watt circuit, so I was wondering what was delta between the 2. Also, I wanted to know what would be the benefit of building 18watter TMB with 36Watt circuit.

Those are some great sounding clips.

Regards,

-gkr
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Post by krash »

well, the 36W has 2x as much power and draws 2x as much current, requires bigger transformers and different rectifier. So whatever power-stage and power-supply tone contribution you find with the 18W, expect it to be different in a 36W.

If you're using a MV amp and turning the master down, then I'd think they will sound really similar presuming the same preamp design. Once you get them cranked then all bets are off because you are driving the speaker a lot harder and putting the transformer and power supply into a very different load condition.

My 36W has a whole lot more bottom end than my 18W FWIW, but the circuits are not all that similar between my amps.
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Post by zaphod_phil »

There are a number of variations of the 18W and 36W amps. For example, this particular schematic has Richie's "Richamp" version, where the "Normal" channel preamp triode is actually brought into the TMB channel preamp - http://www.18watt.com/modules.php?name= ... ad&id=4410 This means that both channels become TMB channels, with similar gain levels, just that the "Normal" one has an extra tone control in addition to the TMB controls they both share. So very little Normal about that! :lol: This variation also has switchable negative feedback.

In general, most people feall that they get a more clean headroom and possibly a beefier tone with a 36W, although when running flat out the 36W will only sound fractionally louder than the 18W. As I'm not a huge fan of the joys of clean headroom, I'm more than happy with a regular 18W. :D
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Nature abhors a clean tube amp

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Post by krash »

the difference for me is that my 36W CAN make a non-saturated tone at rock gig volume levels, while my 18W has to run flat-out at gigs to keep up with a rock band. now I built a channel-switching amp to take to gigs with a 36W-influenced power section, knowing I needed flexibility to do cleanish tones for rhythm guitar & the like and also to cover gainy/overdrive tones especially for rock lead stuff. if you need any kind of cleanish tone at rock gig volume levels, I think 36W and efficient speakers are a must-have.
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Post by zaphod_phil »

Yes, that's the key difference. If you want to be able to play loud cleans, you really need the 36W. I prefer to play loud dirties, so 18 watts is plenty loud for me. :D Anyway, clean is for sissies! :lol:
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Post by Great_King_Rat »

zaphod_phil wrote:There are a number of variations of the 18W and 36W amps. For example, this particular schematic has Richie's "Richamp" version, where the "Normal" channel preamp triode is actually brought into the TMB channel preamp - http://www.18watt.com/modules.php?name= ... ad&id=4410 This means that both channels become TMB channels, with similar gain levels, just that the "Normal" one has an extra tone control in addition to the TMB controls they both share. So very little Normal about that! :lol: This variation also has switchable negative feedback.

In general, most people feall that they get a more clean headroom and possibly a beefier tone with a 36W, although when running flat out the 36W will only sound fractionally louder than the 18W. As I'm not a huge fan of the joys of clean headroom, I'm more than happy with a regular 18W. :D
Thanks Dr.

The amp I bought used to belong to Rock-On!! Reading through posts I found out that it was built by Richie and in fact it has a NFB switch as well. From what I read now is that normal channel shares the EQ with TMB. Is my assumption correct?

Thanks
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Post by Turmoil »

"Anyway, clean is for sissies! "

Ohhh, Burn!
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Post by keith »

Use the 18 watt JA front end(preamp) with the 36 watt power end. You'll have a great, but louder 18 watt style amp. Not much clean, but thats what Fender amps are for.

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Post by krash »

actually I think the 18W clean tone is gorgeous and I use it probably more frequently than the OD tone. My 36W also has a gorgeous clean tone, maybe my favorite of any amp I've played, alongside some killer OD tones. These are really flexible amps (depending of course on which of the zillion variations you build ... speaking generally of the "normal" 18W with trem).

When I really need to crank up the crunch, I use my trainwreck-ized Princeton Reverb. Now there's an amp with some seriously mean distortion.

We took the 36W to a blues jam and it's loud enough with a strat and you know that "Texas Blues" kind of just-a-bit-of-crunch to play with a rather loud blues band. The 18W on the other hand, had to be dimed and played with humbuckers to play with the same band and just didn't fit in correctly. So there's something to be said for having that extra "headroom" of the 36W, in terms of versatility or purpose.
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Post by Graydon »

I've built a couple 36W amps with my 18W preamp and a 36W power amp. The 36W sounds very much like the 18W but louder. The really nice thing about it is that since it is louder, the clean tones are more usable. As Krash mentions, the cleans are gorgeous. They are sparkly with a thick midrange and a realyl solid bottom end.
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