An amp that i've just built for a friend.

[Toe-Knee]

The guy who i did this for had a dual recto and was growing tired of it as he just wanted something that was straight to the point and hifi sounding.

So we worked through a list of what he liked/disliked about the DR and if there was anything in other amps that he really liked and came to the conclusion that he wanted something built around the SLO circuit.

The only deviations from the stock circuit is the slope has been adjusted slightly to shift the mids a bit and the heaters have been elevated with a DC reference of 43v this is great as it not only reduces the noisefloor considerably but it also prolongs the life of cathode followers.

Here's a few highlights

Partially populated Preamp PCB

Populated power amp with low ESR nichicon electrolytics

Almost complete preamp with F&T electrolytics

The headshell when i got it needed some slight modifications to make the grill line up with the chassis

Front panel

Power valve & Preamp Valve heater bridge/ FCT

Lamp wiring from the heater filaments

Power amp wiring before it got tidied up

Preamp Wiring Note the purple wire going to the PCB standoff this is connected to the input jack and is in series with a 0.01uf capacitor which removes any potential RF interference as it enters the amp

Tonestack & presence/depth pot wiring

Testing before it all gets boxed up

Front shot notice the grill is now inline

Rear Shot - External bias adjustment, slave out, fx loop

Final testing before collection

 

[Toe-Knee]

Re: An amp that i've just built for a friend.

I noticed originally the picture sizes messed up the formatting. I presumed they would auto resize but they didnt so i adjusted them.

A bit more info about the parts that were used in the amp.

Resistors were Vishay/Sprague CCF60 metal film with a 1% tolerance
there were also some panasonic power resistors used too (the blue ones)
and a few koa speer that were also 1% tolerance.

The coupling/decoupling caps were Sprague Orange Drops from the 715p & 225p range and also there are 4 Illinois caps in there too.

Electrolytics were all Nichicon or F&T all how very low ripple ratings.

The valves were all JJ. ECC83s in the preamp and 6L6GC in the power amp.

The transformers were custom made by Bud Purvine @ Onetics the PT being spec'd seperately and the OT was his standard Hi-Def model the choke was also a 5H Onetics.

 

[Maynardo]

Re: An amp that i've just built for a friend.

Great looking!!!, is 50 watts right?... I only see two power tubes.

A demo would be killer!

 

[misterwhizzy]

Re: An amp that i've just built for a friend.

That is beautiful. Your work looks impeccable, sir. Seriously, any ambition I ever had to build an amp has just been shot down in flames. I could never hope to match the quality of your work. If it sounds half as good as it looks, it's probably right in the same league as a real SLO.

 

[JOLLY]

Re: An amp that i've just built for a friend.

Very very nice. I'm jealous of your work and ability to do that.

 

[trevorus]

Re: An amp that i've just built for a friend.

That's a sweet looking amp. Where did you source the board and the head shell? I've been meaning to get some regular tag board and do some new amp projects, but it won't be until the summer, for sure. Now I want to go solder up some stuff rather than do this massive pile of homework I have...

 

[Toe-Knee]

Re: An amp that i've just built for a friend.

Great looking!!!, is 50 watts right?... I only see two power tubes.

A demo would be killer!

yeah its 50w and can be run with pretty much any octal valve type.

I don't have any good clips of this amp inparticular but heres a very quick one that i put together in the first test but it was done with a singstar mic as ive lent my mics to a friend.

http://soundcloud.com/diy-audio/d-mackay

and heres a few clips of my amp (the white one) that were recorded a bit better

http://soundcloud.com/diy-audio/boyes-superlead-50w-with

http://soundcloud.com/diy-audio/ola

Also note i am useless at mixing. These clips really don't do the amps justice

 

[Toe-Knee]

Re: An amp that i've just built for a friend.

That's a sweet looking amp. Where did you source the board and the head shell? I've been meaning to get some regular tag board and do some new amp projects, but it won't be until the summer, for sure. Now I want to go solder up some stuff rather than do this massive pile of homework I have...

the PCBS were from a member on the sloclone forums called smashguitars and the headshell was from an italian company called brownsound as was the chassis but i wont be using them again after this....

 

[JOLLY]

Re: An amp that i've just built for a friend.

Sounds damn good to me.

 

[Toe-Knee]

Re: An amp that i've just built for a friend.

That is beautiful. Your work looks impeccable, sir. Seriously, any ambition I ever had to build an amp has just been shot down in flames. I could never hope to match the quality of your work. If it sounds half as good as it looks, it's probably right in the same league as a real SLO.

Dont let this put you off.

This is only my 4th amp that i've built.

it just takes a lot of patience and planning and many many hours of research on how not to kill yourself

If you are commited to putting the time in its rather easy. I went from doing a BYOC tubescreamer kit straight to one of these. I probably spent about 3-4 months reading up on how it all works and the risks and also where other people had gone wrong with this particular type of amp.

 

[misterwhizzy]

Re: An amp that i've just built for a friend.

But do you understand that you make it look entirely too easy?

Have you ever watched a good guitar player just blaze through his set with no effort at all? It's deflating. You try and try and try, and you're nowhere near half as good as one of those guys. (This is all personal experience. Obviously, I'm not talking about you in particular.) If I didn't love playing guitar, I would have given it up years ago. But I know I'm never going to get to the level of one of those guys.

Really, I'm just complimenting you, because your work looks clean and perfect. I think of the work I've put in over the years soldering pickups and electronics and doing a few pedal mods here and there, and I'm never confident about things working properly.

Let me ask you this, and I'm sorry to derail the topic, but how do you go about testing the amps? You can't really fire things up until it's close to done, right? I guess once you get the rectifier wired in, you could test whether you're getting a good voltage to the board. But aren't you stuck with that until you get the OT wired up? Meaning the rest of the amplifier?

 

[Maynardo]

Re: An amp that i've just built for a friend.

wow... sounds br00tal and then some

 

[DankStar]

Re: An amp that i've just built for a friend.

Skills alert!

 

[Vasshu the humanoid typhoon]

Re: An amp that i've just built for a friend.

Niiiiice...love your work...looks neat and clean!
And it sounds great too!

 

[Toe-Knee]

Re: An amp that i've just built for a friend.

But do you understand that you make it look entirely too easy?

Have you ever watched a good guitar player just blaze through his set with no effort at all? It's deflating. You try and try and try, and you're nowhere near half as good as one of those guys. (This is all personal experience. Obviously, I'm not talking about you in particular.) If I didn't love playing guitar, I would have given it up years ago. But I know I'm never going to get to the level of one of those guys.

I know exactly what you mean with this i always feel that i will never get to where people i respect to be are.

Let me ask you this, and I'm sorry to derail the topic, but how do you go about testing the amps? You can't really fire things up until it's close to done, right? I guess once you get the rectifier wired in, you could test whether you're getting a good voltage to the board. But aren't you stuck with that until you get the OT wired up? Meaning the rest of the amplifier?

Its not problem derailing the topic :cool2:

There are tests that you can do along the way such as checking the voltages/resistance is right across the transformer primaries & secondaries which is something that should always be done straight away as its a pain to have to dissasemble the entire amp to get them out.

As for other tests you can check for good continuity amongst your grounds and across your flying leads to make sure there are no breaks etc in the wires.

But the majority of electrical testing is done once the amp is finished.

One thing to be sure to do is visually check everything to make sure its fine.

in this build at first i blew a few fuses and i couldnt for the life in me figure out why and it turned out that one of the high voltage wires had got knicked underneath the power amp pcb mount and was shorting directly to ground.

 

[Toe-Knee]

Re: An amp that i've just built for a friend.

wow... sounds br00tal and then some

Who said you need a boost for metal???

 

[Toe-Knee]

Re: An amp that i've just built for a friend.

and thanks to everyone for your kind comments so far.

 

[stevie_bees]

Re: An amp that i've just built for a friend.

Can I be your friend too Tony???

 

[Toe-Knee]

Re: An amp that i've just built for a friend.

Can I be your friend too Tony???

of course

 

[Chickenwings]

Re: An amp that i've just built for a friend.

wow