thanks, on the subject of transformer layout there are a couple of options.
1) going from left to right have the two output tranformers, then put the power on the rght top corner, and the choke beneath that, which would push the tubes together more in the bottom left.
2) output L, power with choke in the centre nearer the bottom, output R. (T shape).
any reason to go for one over the other?
1) going from left to right have the two output tranformers, then put the power on the rght top corner, and the choke beneath that, which would push the tubes together more in the bottom left.
2) output L, power with choke in the centre nearer the bottom, output R. (T shape).
any reason to go for one over the other?
I laid my hueys out to keep the mains-in and power supply physically separated from the signals, pretty much mains in, power transformer, choke, and CLC supply on one side and all the signal stuff, tube sockets, output transformer, etc on the opposite side for each monoblock. I also kept the various support circuits for the tubes as close to the tube sockets as I could.
I cannot detect any mains hum, just a tiny bit of tube noise with my ear to the speakers.
I suppose if you are doing stereo in one chassis, you could put the mains/PS stuff in the middle, and the signal stuff on the outboard sides, as far away from the mains as you can, or arrange some other way to keep the mains AC away from the signal.
I cannot detect any mains hum, just a tiny bit of tube noise with my ear to the speakers.
I suppose if you are doing stereo in one chassis, you could put the mains/PS stuff in the middle, and the signal stuff on the outboard sides, as far away from the mains as you can, or arrange some other way to keep the mains AC away from the signal.
Top Chassis layout
I did much as gingertube advises--but I put the RCA inputs very close to input tubes. This drew adverse comment from others...
Your boards look very well laid out to me.
Good luck with the rest of your project--it should be a winner....
I'd post images but nothing happens, except for the following:
C:\Documents and Settings\oem\Desktop\BBH2b.jpg[IMG]
[IMG]C:\Documents and Settings\oem\Desktop\BHinaction3a.jpg[IMG]
I'll find some old posts to refer back to.
I did much as gingertube advises--but I put the RCA inputs very close to input tubes. This drew adverse comment from others...
Your boards look very well laid out to me.
Good luck with the rest of your project--it should be a winner....
I'd post images but nothing happens, except for the following:
C:\Documents and Settings\oem\Desktop\BBH2b.jpg[IMG]
[IMG]C:\Documents and Settings\oem\Desktop\BHinaction3a.jpg[IMG]
I'll find some old posts to refer back to.
Thanks. I think i am going to go with the T shape, with the PSU components down the middle. The case is 17 inches wide, so i should have just enough room to prevent hum.
here is a 30 second mockup.
here is a 30 second mockup.
An externally hosted image should be here but it was not working when we last tested it.
Re: Re: Top Chassis layout
Jackomancy: You need to move the images off of your hard drive onto a web address before they will show up in the post. As a fellow http knucklehead, it took me over an hour of screwing around to figure this out when I posted pics of my hueys in an earlier post. Once they are on a web address, you can use the
planet10 said:
Jackomancy: You need to move the images off of your hard drive onto a web address before they will show up in the post. As a fellow http knucklehead, it took me over an hour of screwing around to figure this out when I posted pics of my hueys in an earlier post. Once they are on a web address, you can use the
Posting pix
Many thanks boywonder, Planet 10 gave me similar sage advice this and last time, but old age/advancing senility make some of these little technicalities hard to grapple with.
Another of the problems is the image containing website does not retain it indefinitely, eg Flypicture. Less sure of imageshack, and probably used it wrongly this time, only posting an URL, not an image.
All in all making this wonderful facility not quite as user friendly as it could be, except for younger nimbler brains well used to computer stuff.....
Have a Merry Xmas!!
Many thanks boywonder, Planet 10 gave me similar sage advice this and last time, but old age/advancing senility make some of these little technicalities hard to grapple with.
Another of the problems is the image containing website does not retain it indefinitely, eg Flypicture. Less sure of imageshack, and probably used it wrongly this time, only posting an URL, not an image.
All in all making this wonderful facility not quite as user friendly as it could be, except for younger nimbler brains well used to computer stuff.....
Have a Merry Xmas!!
ok, i think i am there on the layout - heres my template. IF anyone has any input please speak up - I am very open to input.
An externally hosted image should be here but it was not working when we last tested it.
Chassis Top Layout
Adamus,
That is the layout I used, and while not nicely symmetrical with power supply medially, I believe it is superior in minimizing interactions between PS and amp proper. And is exactly what gingertube suggested, after all....
Cheers and have a merry Xmas.
jackomancy
![IMGDEAD]](/community/proxy.php?image=http%3A%2F%2F%5BIMGDEAD%5Dhttp%3A%2F%2Fimg361.imageshack.us%2Fimg361%2F4391%2Fbbh2bev3.jpg%5B%2FIMGDEAD%5D&hash=2d61bdfcea6447b4e518deddcf3ed343)
Hooray! Pix posting success at last.....
Adamus,
That is the layout I used, and while not nicely symmetrical with power supply medially, I believe it is superior in minimizing interactions between PS and amp proper. And is exactly what gingertube suggested, after all....
Cheers and have a merry Xmas.
jackomancy
Hooray! Pix posting success at last.....
initial measurements
b+ 230
cathodes of 6p14p
1) 1.63
2)1.64
3)1.63
4) 1.64
voltage across 18ohm resistor in bias block is approx 0.81v.
any clever ideas for what is bring the b+ down?
As for moving away from the schematic, i used a clc powersupply (6.8uf, 5h, 220uf).
I also used 220nf caps at the ct of the output transformers (schematic shows 100uf).
b+ 230
cathodes of 6p14p
1) 1.63
2)1.64
3)1.63
4) 1.64
voltage across 18ohm resistor in bias block is approx 0.81v.
any clever ideas for what is bring the b+ down?
As for moving away from the schematic, i used a clc powersupply (6.8uf, 5h, 220uf).
I also used 220nf caps at the ct of the output transformers (schematic shows 100uf).
Adamus, have you tested your CCSs out of circuit? Use a 12V DC supply with a load resistor of around 100 ohm to limit the current to max 100mA to avoid blowing those "3-legged fuses".
From your measurements it seems that the current per tube is 45mA which could be a little high.
The cathode voltage of only 1.6V is low. It should probly be around 8V.
Normally it should be safe to run with tubes in only one channel. However, if the PS is the only current limitor, you could blow the tubes.
SveinB.
From your measurements it seems that the current per tube is 45mA which could be a little high.
The cathode voltage of only 1.6V is low. It should probly be around 8V.
Normally it should be safe to run with tubes in only one channel. However, if the PS is the only current limitor, you could blow the tubes.
SveinB.
ok, the bias blocks are the fault.
With a nine volt battery to test, i get 0.563 over the 18r.
With a 13.8v supply they I get 0.773 over the 18r.
Again, traced the schematic and they look good, and it must be a systematic error across each block as they all do the same thing.
hmmm, may just rebuild them.
Would that be enough to bring the b+ down 70 volts?
With a nine volt battery to test, i get 0.563 over the 18r.
With a 13.8v supply they I get 0.773 over the 18r.
Again, traced the schematic and they look good, and it must be a systematic error across each block as they all do the same thing.
hmmm, may just rebuild them.
Would that be enough to bring the b+ down 70 volts?
For testing the CCS I propose to measure the actual current. The voltage across the resistor could be misleading if substantial current take a different path.
From your measurements it might look like the collector of the BC547 is not correctly connected to the base of the MJE. In that case the current would flow through the MJE, and through the base-emitter junction of the BC547, each with a voltage drop of 0.6-0-8V.
SveinB.
From your measurements it might look like the collector of the BC547 is not correctly connected to the base of the MJE. In that case the current would flow through the MJE, and through the base-emitter junction of the BC547, each with a voltage drop of 0.6-0-8V.
SveinB.