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Author Topic: What I've been up to for the last 3 days...  (Read 11863 times)

juansolo

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What I've been up to for the last 3 days...
« on: September 24, 2012, 07:17:14 PM »
Most enjoyable...



Sanity checking tomorrow followed by power.
When you´re racing, it's life. Anything that happens before or after is just pies.

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HTH AMPS

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Re: What I've been up to for the last 3 days...
« Reply #1 on: September 24, 2012, 07:24:38 PM »
Two octal bases and one 9-pin?  :?

(edit)... managed to find the schematic, so its parallel SE design - I like it  :D

I'd still look to add a second ECC83 and get that amp grinding  :lol:

Maybe make the circuit more 'tweed'.


dave_mc

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Re: What I've been up to for the last 3 days...
« Reply #3 on: September 24, 2012, 07:45:42 PM »
what is it? EDIT: ah right, found it, it's an ampmaker kit.

looks nice (to my completely uneducated eye :lol: )

juansolo

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Re: What I've been up to for the last 3 days...
« Reply #4 on: September 24, 2012, 08:16:08 PM »
Yeah it's an Ampmaker Double Six. Thought I'd start with a kit for my first. Get into good practices and wotnot.

For the interested, this is the schematic for it. Slightly unusual as there are Fendery bits, but it has a Baxandall tone stack with a mid cut added later in the circuit. Should be interesting! You can stick the Fender stack in there if you like and the turrets are on the board along with the instructions on the Forum.

What I liked about the blurb is that it's primarily a clean amp. Though it's switchable between 12 to 6 and 1 watts, and can allegedly crunch up nicely when you do. Saying that, I'm going for clean headroom so even though I'm building it with 6V6 tubes, t'll be going to 6L6s when it's all tested and working as it'll need a couple of resistor changes. I also managed to snag a pair of 10" alnico speakers for next to bugger all for it.
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Dmoney

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Re: What I've been up to for the last 3 days...
« Reply #5 on: September 24, 2012, 08:33:52 PM »
Is that parallel single ended with cathode bias?  I've never looked at a schematic with a power stage like that.
The mid control being later in the preamp than the treble and bass, and inside the negative feedback loop is interesting.
Switch between the high voltage secondary and the rectifier seems interesting too.

interesting!


Twinfan

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Re: What I've been up to for the last 3 days...
« Reply #6 on: September 24, 2012, 09:00:13 PM »
Nice work John, tidy wiring as always!

juansolo

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Re: What I've been up to for the last 3 days...
« Reply #7 on: September 24, 2012, 09:13:38 PM »
Is that parallel single ended with cathode bias?  I've never looked at a schematic with a power stage like that.
The mid control being later in the preamp than the treble and bass, and inside the negative feedback loop is interesting.
Switch between the high voltage secondary and the rectifier seems interesting too.

interesting!



Certainly seems to be. I have no idea at all what this is going to be like. As you say; interesting!
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jpfamps

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Re: What I've been up to for the last 3 days...
« Reply #8 on: September 24, 2012, 09:17:30 PM »
Good work.

It's an interesting circuit, and very different from most other kits, which are often copies of the usual suspects.....

The mid-cut "T-filter" is used on several Gibson amps and some Traynor amps, although usually with fixed attenuation.

As pointed out above, it's interesting that it's inside the feedback loop.

I would be tempted to experiment with opening the feedback loop as this should give you more gain.

Parallel single ended designs are rare (don't Laney have a quad single ended amp?).

I think this is because if you are going to use two valves, you will get more power in push-pull configuration, and you can use a smaller and hence cheaper transformer.

You also can have more issues with oscillation in parallel SE, which probably explains the 1 ohm anode resistors on the power valves.

When are we getting the sound samples?

dave_mc

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Re: What I've been up to for the last 3 days...
« Reply #9 on: September 24, 2012, 10:09:41 PM »
^ yeah the lionheart (laney's parallel single-ended amp) :)

Yeah it's an Ampmaker Double Six. Thought I'd start with a kit for my first. Get into good practices and wotnot.

For the interested, this is the schematic for it. Slightly unusual as there are Fendery bits, but it has a Baxandall tone stack with a mid cut added later in the circuit. Should be interesting! You can stick the Fender stack in there if you like and the turrets are on the board along with the instructions on the Forum.

What I liked about the blurb is that it's primarily a clean amp. Though it's switchable between 12 to 6 and 1 watts, and can allegedly crunch up nicely when you do. Saying that, I'm going for clean headroom so even though I'm building it with 6V6 tubes, t'll be going to 6L6s when it's all tested and working as it'll need a couple of resistor changes. I also managed to snag a pair of 10" alnico speakers for next to bugger all for it.

sounds very nice. what speakers did you snag?

jpfamps

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Re: What I've been up to for the last 3 days...
« Reply #10 on: September 24, 2012, 10:24:12 PM »
Quote from: dave_mc
^ yeah the lionheart (laney's parallel single-ended amp) :)

Thought I wasn't going mad!

juansolo

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Re: What I've been up to for the last 3 days...
« Reply #11 on: September 25, 2012, 08:39:18 AM »
sounds very nice. what speakers did you snag?

A pair of 10" Eminence Legend 1028Ks. Alnico jobbies. For the price (they were £35 a pop each) it'd have been rude not to. If I don't like them, I'll flog 'em and try something else. Though word has it that the work well with clean amps.
« Last Edit: September 25, 2012, 08:44:55 AM by juansolo »
When you´re racing, it's life. Anything that happens before or after is just pies.

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juansolo

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Re: What I've been up to for the last 3 days...
« Reply #12 on: September 25, 2012, 05:18:13 PM »
Success!



Oh I like this! It's not quite as loud as I  expected (which is a bonus), but it's clean all the way around the dial. Then you kick the boost (throws out the tone stack) and yep, there's quite a bit of crunch there. Responds really well to pedals on the front of it too. Lovely clean tone. Which was what I was after, though it doesn't dirty up as nicely as my MJW does, unsurprisingly.

The 6L6s sound much nicer than the 6V6s. However I'm not entirely sure they're running optimally, nor do I think I can when I'm limited to a 15w PSU. Still they'll last a lot longer.  It's got a NOS RFT in the pre-stage after swapping a few around.

The watts switch works. It's really quiet and breaks up easily on 1W. You can talk over it. Obviously it loses a tonne of headroom. But it does what it does well.

Over all really pleased with it. Can't wait for it to get boxed up.
When you´re racing, it's life. Anything that happens before or after is just pies.

http://stompage.juansolo.co.uk

HTH AMPS

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Re: What I've been up to for the last 3 days...
« Reply #13 on: September 25, 2012, 05:49:00 PM »
Quote from: dave_mc
^ yeah the lionheart (laney's parallel single-ended amp) :)

Thought I wasn't going mad!

Isn't that four (yes four) EL34s in parallel SE? - I'd love to see the schematic.  Apparently they're approaching the power supply from a non-traditional angle to get round having a huuuuuuge PT for the current requirements of those EL34s running class A.

marauder

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Re: What I've been up to for the last 3 days...
« Reply #14 on: September 25, 2012, 05:55:19 PM »
Isn't that four (yes four) EL34s in parallel SE? - I'd love to see the schematic.  Apparently they're approaching the power supply from a non-traditional angle to get round having a huuuuuuge PT for the current requirements of those EL34s running class A.

I've got the 20W Lionheart which is 4xEL84s in parallel SE.  The EL34 model has 5 in parallel!!  Mine has a toroidal PT.