HI Bernd
yes channel 2 is the high gain channel, the +/++ is what i was refering to 
i cannot record it (sorry) and the fat switch didn't seem to make any difference.
when i flick the + to ++ all is OK until i strum.
if i lightly tap the strings i get sound, as soon as i strum or pick a string it "cuts out". there is still sound coming out of the amp, but it is so quiet it is barely audible.
its almost as if too much signal causes the amp to drop the volume right down.
any ideas?
one more small problem
when i go to high gain mode on channel 2, i get about a second of sound, then it cuts out. if i switch off and back again i get another second then silence.
i thiught it might be a bad solder joint, but every timt i reset the switch it works for about 1 second.
any thoughts?
Thank you both!!!!
that has cured the squeal.
I have read all the voltages and they are all OK, the high voltages were between 6 and 9% over the schematic.
By the way i really do appreciate all the help you are giving me, I AM EXTREMELY grateful
Hi Bernd
I'm not really sure what that means
but I have checked my layout again and it matches the photo of the wiring diagram exactly colour for colour at each tube.
HI GUys
so I connected a speaker and power, let the tubes warm for a minute and then flicked the standby. after about 2 seconds i heard a high pitched squeal. so i killed the power (all pots are full off).
the same for channel 2.
all my wiring looks correct. but there must be something wrong right?
Can any one help me?
So, the manual says;
"chk the res of the OT after assembly to make sure everything wired correctly. At teh primry side you should measure about 500Ohm, at the secondary side you should measure about 1 Ohm at the 4 Ohm (I missread this as 10 Ohm -DOH) I get 0.7
about 1.2 at the 8Ohm, i get 0.9 and 1.4 ohm at teh 16ohm, i get 1.2.
so those all seem ok.
I measured between the star ground and teh out put sockets for 4, 8, 16 ohms.
I didn't know where to measure the primary between though.
with your advice I measured between 6 and 12 and between 7 and 13. both readings where 250 ohm (but 6 and 7 are connected!)
between 12 and 13 i get approx 500 ohm (
as for stopping build, I carried on wiring components, but did not want to power up for fear of damaging something.
so I am at page 30 "checking and testing"
I have checked all ground leads. gone over teh woring diagram a couple of times.
now i need to connect a speaker and then power up (I only have 16 ohm speakers, persumably it does not have to be an 8 ohm as stated by manual (as long as plugged into correct output socket)?
once Ive done this i need to add tubes etc
if you guys reckon my readings are OK for OT I will move on.
this is my wiring completed. (sorry for dodgy picture, taken with my phone)
[Blockierte Grafik: http://img.photobucket.com/albums/v369/p-traxJapan1/4245_107804309008_622629008_2552121.jpg]
thanks for the input guys.
I will measure again.
BUT, can you help further by describing exactly where the measurement points are please?
sorry for the remedial questions, this is the second amp i have built and I am not familiar with all the terms (the first was a 1/2watt gilmore jnr, which is much simpler and didn't require any testing).
As I have not had any replies to the 4 emails sent to Klaus and Martin I thought I would post here, can someone offer advise as I cannot get any customer support via email;
On page 19 of the manual it says to check the resistance of the output transformer.
When I connect probes from ground to the connections on the 4,8&16 ohm speaker sockets I get 0.7, 0.9, & 1.2 ohms respectively (this is incorrect according to manual).
I do not know where to measure the primary side (I have tried between ground and the various blue wires and get a resistance that climbs slowly to about 75.7 kohms).
Am I measuring incorrectly? Is the transformer faulty?
i want to complet this build but have had aseveral weeks delay waiting for an answer.
cheers
