Tube Amp Archive

there will be updates coming in the next couple of months. I had a few financial setbacks (doesn't it just seem like that's always the story) that kind of put this build on hold for about 6 months. One update I do have is that I have a Celestion Greenback 10" that was bought for me - gotta say I'm r...

Hey fellow Aussie, :-) I use evatco.com.au and ebay for specialist parts. And futurlec.com.au for general parts (resistors, caps) at cheap prices if you can wait a week or two. For transformers ... If you find a good, cheap option, please let me know! I just can't bring myself to buy from evatco it...

Yeah you're probably right.

Well now I'm just waitin on a bit of cash to order the parts. So hopefully get them ordered in the next couple weeks.

Just on a previous question what shop does everyone use for parts?

It was some kind of new release but it had a pretty good celestion/vox tone (within my budget constraints).

out of curiosity is there a simple way to throw in an effects loop in this design? I'm a reverb fan and in a worst case scenario I can just throw it in the front end.

Hi Tony, Yeah that seems to be what I've been reading/thinking from youtube videos etc. Unfortunately for me in Australia (I dont know what its like for you guys elsewhere in the world) its really difficult to go and try out speakers so I have to pretty much research and take the plunge. I do have a...

I'm currently looking at where to buy parts - I've priced things from antique electronic supply. Does anyone have any suggestions? baring in mind that I have to have it sent to Australia (the only reason I don't buy local is because its about +100% to +%400 on each component cost). does anyone have ...

I just thought I'd keep a running update so every one knows the project isnt dead - I've decided to drop the cathode caps to 2.2uf as is seems like a more common design and I dont want to over do it with the gain. changing the layout to facilitate the aforementioned grounding scheme I measured the p...

Sorry I should have clarified that I haven't yet sorted out all the windings on the transformer that I have so I haven't filed in the specifics of the taps yet. So you think I should move the preamp filters to the preamp side of the board and ground them near the preamp? What do you mean up the fila...

That’s interesting, and it could be just complete novices like me spoiling their good rep all over the internet but as I stated in the first post I've always loved the sound of the top boost preamp, so maybe I'll have a crack at the original Vox AC4 with its ef86 channel at a later date. (Just becau...

I've had a crack at a layout...

Any glaring errors? (be kind I've never done one before)

Sorry Surfsup, if you hadn't already guessed I'm very new at this. So what you're suggesting is upping the value of the preamp filter caps to 25uF. Would there be any advantage in upping the value of all of them? I only used 16uf because the original with a valve rectifier used them - and in an effo...

Ok so I've been tinkering with the design based off Colossal's suggestions and looking at the Vox AC4TV schematic. There is:
1) More filtering
2) a 5H 90ma choke
3) grid resistor on EL84
4) Master Volume
5) Reduced Bypass Caps

So thoughts on the improved schematic? is it improved?

WOW thats exactly the kind of feed back I wanted/needed. Thank you! The master volume does sound like a good idea for cutting down some of the preamp gain and getting some cleaner tones. I really wasn't sure about how much gain the el84 would need as the original used an EF86 (not a tube I'm too fam...

Ok thanks for that clarification I wasn't aware that thats how this forum operated. I'll edit out the 3rd set of images. So does no one have any ideas on the design? I have another question actually in the original topboost design they have a cap (32uf) hanging off the B+ going to the preamp - this ...

I just logged on with another computer - can anyone else even see the attachments? Because I cant on other computers Here are some photobucket links for those that cant see them [IMG:1024:504]http://i1189.photobucket.com/albums/z431/whichello/VoxAC4topboost.png[/img] [IMG:1022:385]http://i1189.photo...