DR504 compared to a Sound City L50+

[lffish133]

Hey Guys I was wondering if you could help me by providing some input. I have been wanting to build my own DR504 because I cannot afford a vintage one although I would love to have one. I recently ran across a decent deal on a Sound City L50+, in my opinion it would be cool to have a real vintage amp, I know that this amp is not the same as a DR504, it has active EQ, no master volume, and a sensitivity switch on the back. I also know that it is not nearly as sought after as a L100. In terms of sound and functionality, how does it compare to the real deal? The L50+ is actually on eBay right now, http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0043477827, is this a good deal? It seems like it is to me. I am still trying to educate myself on all of this.
Thanks,
Kam

[gldtp99]

A Sound City 50+ has very little in common with a Classic Hiwatt DR504---- it has an active Mk4 preamp that accounts for the noisy backround wash that the seller says is "easily fixable"--- if it was so easy to fix then why is he selling it?---- some people really like these amps for what they are, and that's cool. I had one several yrs ago and it was ok--- but i liked my Fender Bandmasters and other amps better. My DR504 clones i've built are much better amps that my SC 50+ was.
I've converted several Sound City 120's to Hiwatt preamps and i own two Sound City L100's, along with other Sound City amps.
The SC 50+ has a completely different layout that a SC L100, 120 or the Classic Hiwatts--- also the chassis is sized/shaped much differently----- maybe a 50+ could be converted to a DR504 but it would be so much easier to buy a new DR504 kit from Dr. Hiwatt.
The Sound City L100 and 120's are constructed along the same lines, roughly, as the Classic Hiwatts so they are more like Hiwatt cousins. The 50 Plus is so different in design and construction that it shouldn't even be considered to be in the same family...............gldtp99

[lffish133]

Hey gldtp99, thanks for your response, those were all of my thoughts about the amp as well, I just wanted to make sure that it wasn't a good choice, looks like I will be building one of Doc Hiwatt's kits! Thanks again.

[Toru_Hiramatsu]

Hi lffish133,

I bought a Sound City 50 Plus Mark IV from a bad "Power Seller" on eBay.
That amp had a power transformer replaced from Partridge to that of Marshall JCM800 50w (!), one cap near the power transformer (fortunately, it was the Partridge one) was nearly dead that almost killed me when playing, and the speaker output jacks were dengerously wired (if you power-on the SC 50+ without the speaker, the amp could die),

All I had to do were:

1. Re-wiring of the speaker output jacks like HIWATT style so that the amp won't die if I accidentally power-on the amp without any speakers connected.
2. Replacing all the paper filmed capacitors from the old and neary dead ones to JJ's hi-fi caps.
3. Replacing the output transformer from Marshall to Heyboer's Partridge for CUSTOM HIWATT 50 and modifying the power-amp section the same as mhuss's schematic.

I don't recommend you to buy SC, it is dengerous in many points.

However, I do like this SC's active equalizer + DR504 power amp, so I'm content with this amp.

[Toru_Hiramatsu]

> That amp had a power transformer replaced from Partridge to that of Marshall JCM800 50w

Oops, it was my mistake. That amp had a Marshall JCM800's OUTPUT transformer.