[philodox]

That amp looks great jarthel, nice work!

 

[AndrewFischer]

Quote:

Originally Posted by jarthel /img/forum/go_quote.gif ps. you can't cut the single board because there are things that are shared between the two.

ahh. I never looked at the layout. I assumed you could cut a few traces, maybe tack on a part or two and get the cathode follower configuration.

In any case the boards I'm ordering will have the cathode follower option.

 

[headphonejunkie]

I wish I got the rev b bds. They have a few more tube/heater options. The rev A should work fine too.

 

[jarthel]

Quote:

Originally Posted by AndrewFischer /img/forum/go_quote.gif In any case the boards I'm ordering will have the cathode follower option.

it seems all the new boards has this option. but you can still use the original design.

If I were you, I would ask around in diyaudio and AA and see if people have built the cathode-follower version.

=========

more listening thoughts:

put in metallica, prodigy, fat boy slim and mozart.

there's a bit of harshness in the highs. maybe "harshness" is not the right term but the highs are definitely discernable.

with prodigy and fat boy, the amp is not afraid to give "ooommmppphhh" when required. I was swinging my butt to the tune. I'm using DT880 which some people have said is bass-shy.

with mozart, there is a bit of "sweetness" to the music. It's not very "sweet" but somehow you know it can get better.

 

[jarthel]

Quote:

Originally Posted by headphonejunkie /img/forum/go_quote.gif I wish I got the rev b bds. They have a few more tube/heater options. The rev A should work fine too.

but not all are suitable though for headphone use

but in case all are suitable, would you be rolling them in? the resistor values and B+ voltage you've used might not be suitable for other tubes. like 6dj8 (not 6922 and 7308) is limited to 150V. some tubes might prefer a higher B+

 

[headphonejunkie]

You would have to make changes accordingly. I do not think all would be that easy to just roll in. If you download the pdf file from broskies site you will see in the back all the tube types available and the voltages, etc...It also shows how to configure the mono bds as either a line stage or a headphone amp.

 

[jarthel]

drastic measures on the DC heater supply!

I have to cut the PCB in half. The heatsink used to be "floating" above the aluminum chassis but it's getting hot. So I decided to let it be touching the chassis so the heat is dissipated to the chassis as well. seems to be working fine for now.

 

[headphonejunkie]

Jarthel
How did you connect your ground to your rca's. I have the same and was wondering if there is a different way to connect the ground other than trying to solder to them. The solder does not seem to work to well. I have had my ground come off at least twice on these type of rca's.

 

[jarthel]

450degrees Celcius on the temp controlled station help me solder the wire to the Cardas RCA jack. I tried 400degrees and it isn't enough.

 

[headphonejunkie]

I am not sure if my weller goes that high. I will have to try it.

Thanks

 

[looser101]

Quote:

Originally Posted by headphonejunkie /img/forum/go_quote.gif Jarthel How did you connect your ground to your rca's. I have the same and was wondering if there is a different way to connect the ground other than trying to solder to them. The solder does not seem to work to well. I have had my ground come off at least twice on these type of rca's.

Use a spare RCA plug and plug it into the jack. Clamp the plug not the jack. Clamping the jack with anything metallic acts as a heatsink and pulls heat away from the jack and makes it hard to heat it enough to solder properly. Put an L shape on the end of your ground wire and hook it in the notch of the first ground ring, this keeps it in place. Put the tip of the soldering iron between the two rings, at the notch/wire, if you can get it to fit. Make sure you have plenty of solder on the tip to help heat transfer. Feed solder to the tip as the jack heats up and let it flow.

Your amp is looking good Jarthel.

~Renato

 

[headphonejunkie]

Thanks looser,
I am going to work on my amp tonight and will try that.

thanks

 

[AndrewFischer]

I ordered a pair of Rev. B 9-pin mono boards this week end. I decided against the octal boards despite the sale. I'd save $10 on the boards but the octal boards limit my tube choices.

 

[headphonejunkie]

The mono bds are nice. I have the rev A's. I am going to be building a CJ optimized with feedback next (just received some of the parts) so the aikido is going to have to wait till next year probably.Hopefully, I will just be able to use the cj's power supply for the aikido. That way I can save a little money.Thanks again for the heads up on the ltspice program andrew.

 

[AndrewFischer]

There was a package in the mailbox today. I figured it was parts I ordered from Whirlpool two weeks ago. Turned out it was the Aikido Rev. B boards I ordered Saturday. Talk about great customer service. The boards are very high quality. The photos don't do them justice. I need to ask Brooksie who makes his boards.

I was playing around with a chassis layout. I think I'll try this one. The mouse is a place holder for a 12V filament transformer. The 270CX has two 6.3V windings but I want to leave room for another transformer. I'm also planning to stuff an Alien DAC in the box but that won't take up any more room than a pair of RCA jacks.