Amp initial testing.

Post by **Nick** » Tue Sep 18, 2007 5:31 pm

Well done

colin.hepburn · Post by **colin.hepburn** » Tue Sep 18, 2007 5:45 pm

Hi Phillip
Congratulations

on getting your amp working it’s a great feeling you get when it all works I cant help thinking when us newbie’s get it wrong and ask the boffins on here for help I get this funny image in my head of then head butting there key board in frustration and saying nooow not like that for god sake
Yes just my humours way of saying thank you for the help and support you all give us

pre65 · Post by **pre65** » Tue Sep 18, 2007 5:46 pm

Hi-thanks to you all for helping me to overcome my (mainly self inflicted) problems.

To be involved with DIY audio is tremendous fun,and knowing that there is a vast pool of knowledge and experience in times of difficulty is a great comfort.

I look forward to meeting you all again at Witham.

Cressy Snr · Post by **Cressy Snr** » Tue Sep 18, 2007 6:04 pm

Well done Philip

I know how good these PT15s sound.
Can't wait to see and hear them on Saturday.

Steve

Dave the bass · Post by **Dave the bass** » Tue Sep 18, 2007 8:39 pm

Whahey! The crazy ol' bloke got the beasty going

Well done Philip, that looks bleedin' neat and proper like.

Another contender for the Gentleman's DHT Challenge?

Looking forward to hearing it in person.

Respect to you sir.

DTB

pre65 · Post by **pre65** » Tue Sep 18, 2007 8:43 pm

Hi-cant wait for the resistors !

I've powered them both up,using CD through my Shunted passive pre into the VoFos.

Must say,that good as they sound,i cant determine if they are "better" than 45,300b and 832 or just,for want of a better description,a bit similar.

Of course i will give them a few hours to run in but the initial impression is a bit undewhelmed !

Perhaps when i can get some more leads made up and can run with Pre3 it might change (for the better).

DTB-i have got some motor run caps left over.2 off 10uf and 2 off 22uf if they are any use to you.

Dave the bass · Post by **Dave the bass** » Tue Sep 18, 2007 8:47 pm

Ta for the offer Philip but I need somewhere between 1->2 uF. I found every thing from 8->60uF at work. They're only a couplasquid, I'll buy the right value after WF.

Cheers for the offer though,

DTB

pre65 · Post by **pre65** » Tue Sep 18, 2007 8:50 pm

andrew Ivimey wrote:
Philip, you said that the PT15 filaments didn't glow red when you tried them a while ago. Is this still the case? This prob. isn't a prob.
Onwards!

Hi Andrew-when i first tested them with 6v to see if the filaments worked i could not see any evidence of redness,but now they are in situ i can see,from the top,a line of red filaments running top to bottom inside the metal casing.

The C3g getts a bit hotter than i thought it might,but not too hot,and the Mullard 150C4 (0A2) does give a small bluish glow at the bottom.

pre65 · Post by **pre65** » Tue Sep 18, 2007 8:53 pm

Dave the bass wrote:Whahey! The crazy ol' bloke got the beasty going

Well done Philip, that looks bleedin' neat and proper like.

Another contender for the Gentleman's DHT Challenge?

Looking forward to hearing it in person.

Respect to you sir.

DTB

Hi Dave-is there a prize for the biggest and heaviest DHT S/E amp ?

Andrew · Post by **Andrew** » Tue Sep 18, 2007 9:03 pm

Congrats Philip

Dave the bass · Post by **Dave the bass** » Tue Sep 18, 2007 9:21 pm

pre65 wrote:
Hi Dave-is there a prize for the biggest and heaviest DHT S/E amp ?

Yes.

Did I mention about DHTski's solid-lead 4ft by 23ft by 47ft high anti vibration mounting platform

DTB

pre65 · Post by **pre65** » Tue Sep 18, 2007 10:10 pm

Hi-now i am still running the two floating DC heating supplies.

Current regulated for the PT15 and a normal bridge + caps for the C3g.

It was mentioned in an earlier post that i may benefit from referencing the C3g supply to chassis earth simply by connecting the return line to earth.

Can this be confirmed,and what benefit should i get ?

Post by **Nick** » Tue Sep 18, 2007 10:55 pm

Can this be confirmed,and what benefit should i get ?

Yes, try that, its hard to say what effect it may have, it depends on what else is going on in the amp.

pre65 · Post by **pre65** » Wed Sep 19, 2007 10:24 am

Hi-bloomey postman did not deliver the resistors today-bottom !

However they are still set up on the floor so i will use today as an opportunity to run them in a bit more so they are in prime condition to blow away the competition (what competition ?

) at the fest.

Playing a Nat King Cole CD late last night did seem to sound a trifle (or is it blancmange) more revealing than i remember.

Compared to 832 PP it does seem a little less "gung ho" but with a lot of the music i listen to possibly more refined and "spacious".

On the hum (or lack of hum) side,with the ear up to the Fostex 206 in the VoFos there is a very slight,muted buzz.Not discernable at the listening position and certainly my quietest valve amp.

Oh,the cupboard is bare again,i have been so intent (or in bungalow) in building amps i've run out of food !! (again) I HATE SHOPPING

pre65 · Post by **pre65** » Thu Sep 20, 2007 8:47 pm

Hi-still running in.

The resistors came this morning but i was out all day (Mums 80th birthday).

One good thing,it does not get as hot as i expected.

Tomorrow i must get up early and get the resistors in,then make up a couple of temporary bases,clear some space in the van for all the bits i'm taking,and if time,breathe.

audio-talk

Amp initial testing.

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