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Well, tell me what you think ( 300b )

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Alright. My 300b amp came in today. I ordered it off a guy who builds them on ebay, and guarantees them..etc. He uses the JElabs 300b stereo SE schematic, ..but after looking inside it i think he used it somewhat loosely.

My whole concept was to buy something to start with, then upgrade it piece by piece so i could hear the difference.

and with that, i submit :
 

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I just think he skimped on a few things, like the quality of binding posts and RCAs ( which seem like radio shack ),...the resistors aren't the standard Riken Ohm, i think the trafos are homebrew. That kinda stuff...

Stuff i couldn't tell pre-auction, but i'm noticing now..

-maz
 
Well let's see, figure $300 for iron and probably another $100 for parts, that's $400. So the guy charged you $150 for putting it together. Punching all those holes and all that mounting and assembly he probably has 20 hrs in it, so that's less than 10 dollars an hour. Bear in mind these are estimates and I have built three tube amps in the last year from scratch. I generally have $270 building a little EL84, and can easily spend two days getting it ready to go. If he told you he followed the schematic that does not mean he bought the same parts unless he tells you that. Gold plated hardware, the good stuff costs a lot of money. So does the more exotic resistors and capacitors. I know that guy that built that JE labs has a lot more than $550 in that amp even without the tubes. The cheapest 300b I know of with cheap tubes is $780 and it's a kit.

Now if he told you he was building it just like the JE Labs right down to the paint then you got a major beef. Bottom line, what's it sound like? You wanted something you could upgrade. Now you can listen to the sound difference as you replace cheaper parts with better ones and see if you hear a difference. You can get the parts list and find out what it all cost and don't forget to include the shipping on parts. It doesn't look like that bad of a build, and I hope it sounds good. Have fun:)
 
It looks really nicely built, but it is a little industrial looking... You could improve it cosmetically.

How about getting a couple of pieces of polished wood and putting them down the sides? And really big volume controls.

Also that switch looks a little "basic", I am a big fan of old skool toggles. :)

If you did a few things like that it would really be "your" amp :D

IOW, pimp it up a little! Get out the chrome and blue LEDs!!!!

:devily: :cool: :innocent: :hug: :hbeat: :headbash: :ill: :joker: :king: :lifesavr: :lock: :yes: :radar:
 
Well, i'll let you guys in on a little plan that i have going.

You might remember if you peruse the analogue forum ( which i'm sure you do ) that i usually post questions about transcriptors turntables.

Well, i'm happy to report that my Saturn turntable with vestigial arm has been restored to its original glory by Michael Gammon. Now, everyone is going to say "well, it looks cool as hell but doesn't sound THAT great"....well, the looks are what i am going for.

I've got a local acrylic dealer whom i'm buying all black acrylic chassis from. ( thanks to peter and his gainclone for the ideas) I'm going to take all the aesthetic concepts in the Saturn deck and apply it to my other components....the 300b amp, a bottlehead line pre, ...still looking for designs for the phono stage, ....
But they will all be standard dimensions, with aluminum knobs, aluminum tops, ...etc if i can encorporate a blue LED on the saturn then maybe i will have one on each component.

So back to the point, the 300b amp chassis will be scraped anyways.....i just wanted a launching point...something to listen to while i build :)

-Maz
 
Hi,

Like CiscoKid, I too built the JE Labs 300b's. CK's and mine are both monoblock versions.

I would not scrap the chassis, paint it and but some wood on the sides. Paint the trannys too.

Replace the rca inputs and binding posts.

I also noticed that the caps are real small and notice only one small oil cap, the others look to be all electrolytic caps. I would start replacing those with bigger caps. Especially in the power supply. Angela Instruments carries the ones most used in scratch building the amp.

Resistors can be replaced with RikenOhm or Tantalum types in the signal path and non inductive types in the power supply. The little gold fin resistors can stay.

Wire used can make a difference and fine silver wire could be an improvement there.

Also, feet for isolation, easy upgrade and reduces micorphonics somewhat.

I cannot tell what type of trannys those are but, this is where a major difference in sound quality is made IMHO, especially the output types. This change can be expensive and goes beyond the $550 you spent for the amp.

Rolling vacuum tubes is part of owning an amp of this type and part of the fun. So you might try different types of tubes, new, nos, ect.

I believe CK spent over $1000.00 for his project and I spent $2500.00 on mine.

All in all, you get what you pay for, but is it worth it ?:nod:
 
Hey Magnetmaz,

Can you tell what the output iron is? It doesn't look like Hammond or Magnequest, or One Electrons for that matter. They are between 100 and 150 apiece. This will tell how much was actually paid for the components versus how much you are getting as "worth".

First off the construction looks very good, so in my opinion that is worth the cost right off. I do not believe he took more than 5 or 6 hours on it. (Sorry fdegrove, but it takes me 5-6 hours to punch 9 tube socket holes and three transformer holes, not to mention the inputs and outputs in steel. This chassis looks like aluminum. It takes me about 2/3rds the time in aluminum.)

But if he got the transformers from Hand Made Transformers, he only paid about 50 bucks apiece. I personally do not know how good they are.

Otherwise, $550 is not bad. Construction underneath also looks very good.

My 2 cents.
Gabe
 
pretty sure the Trafos are hand made. The choke especially has a weird glue-looking brown hardened goo on the laminates. I won't know how they sound for a couple days....but it feels like i am starting from the bare minimum components, and will upgrade as i have money.

The chassis is steel...probably a hammond chassis...riveted on the corners.

I agree with Maybeim..the caps and the connectors will be the first thing i upgrade.

There are rubber feet on the bottom plate of the chassis.

-Maz
 
Just got an email from the guy who sold it to me. I asked who made the trafos, and what type of cap the big orange block was.


his answers :
the orange cap is 15uf 400volts ac its polyprolyne in oil, we wind our own
transformers those are 3400 ohm to 4,8,16 ohm , with a 98% bobbin fill ,
15hz- 45khz 15 watt power rating,
 
Hi Magnetmaz,

I wonder if it is from Handwound. Interesting. He's making a wee bit more than 150 bucks off of you.

As for the chassis... if it is Hammond it will be aluminum. Unless he took the trouble of blasting off the grey primer, or black matte paints the steel ones come in.

Since you say it is rivoted in the corners (not welded?) then it must be manufactured from some other source.

Still... it is nice.

Gabe
 
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