B-Spoke valve pre amp project.

[AlienALX]

OK so I got my kit in today. First thing I looked for was the instructions, it doesn't have any. Thanks, I thought. None of the components were labelled just thrown in a baggy. So not only have I had to learn how to ID components I have also had to name them.

And the body.

OK, so as I said the first thing I had to do was basically separate the enormous mass of components and then ID them. To ID the resistors I used this -

http://www.dannyg.com/examples/res2/resistor.htm

If you are considering any electronics kit I suggest you bookmark that, it will save you crying later.

For the other components I simply ran what was on them into Google, or what was on the board. If the picture matched I had IDed a component.

So, here is what I got.

Note - I have not given them their overall tecnhical names. I have named them to correspond with the board. So I know exactly what goes where, instead of having to ID them all over again and then go "Ah, so 4.7k means 4700 resistance" and etc.

I also got a bit of a kick in the gones when I found out that it would not operate on a AC/DC power supply. IE - you can not run it in DC. It is because it multiplies the voltage somehow, so you must use AC. Big problem, not only are AC/AC power supplies really hard to find (as every one uses DC) but they are expensive. About four times more expensive than a DC unit (so around £30). Eventually some one pointed me to this thing.

For about £7.50. Basically it's a AC/AC 12v unit used for kitchen lighting and comes with its own connector plug.

So the idea is to combine a finished unit with this.

This.

Lots of laquer, and this.

 

[Kaapstad]

You have not said why you are building a valve pre amp and what the advantages are.

I am old and have got a pretty good idea though.

 

[AlienALX]

You have not said why you are building a valve pre amp and what the advantages are.

I am old and have got a pretty good idea though.

If you are running a power amp you need a pre amp. Otherwise it pretty much runs at 100% volume all of the time. Car amps work like that. They have GAIN settings, but yeah, are usually power amps.

Why do I want one? I want to colour the sound. Yes yes, flat EQ you smell if you colour the sound with anything yada yada yada. I like the sound of valves better than transistors. It's as simple as that. People say that Beats headphones are crap and have too much bass etc but what if you are looking for bass?

Yeah, that's about as far as I want that argument to go. Each to his own etc..

Now the reason I want one more than anything is because I do not like the line output volume of most of my sound cards. As thus I want to boost the signal before it gets to the amp, and as I said colour it completely with the sound of valves.

So yeah, that's about it really. Total overall spend was less than £30 all in

 

[hmmblah]

Very cool, can't wait to see what you do with this.

 

[Kaapstad]

If you are running a power amp you need a pre amp. Otherwise it pretty much runs at 100% volume all of the time. Car amps work like that. They have GAIN settings, but yeah, are usually power amps.

Why do I want one? I want to colour the sound. Yes yes, flat EQ you smell if you colour the sound with anything yada yada yada. I like the sound of valves better than transistors. It's as simple as that. People say that Beats headphones are crap and have too much bass etc but what if you are looking for bass?

Yeah, that's about as far as I want that argument to go. Each to his own etc..

Now the reason I want one more than anything is because I do not like the line output volume of most of my sound cards. As thus I want to boost the signal before it gets to the amp, and as I said colour it completely with the sound of valves.

So yeah, that's about it really. Total overall spend was less than £30 all in

I thought you were going to say the above about valves colouring the sound.

Why not go the whole way and build a valve power amp too.

On another subject one of the funniest uses of valves I came across was when the USA first got their hands on a Mig 25 fighter jet, it was full of valves instead of transistors.

At first the Americans had a real good laugh at the Soviet Unions top fighter jet using such ancient technology, then they crapped themselves when they realised that valves are not effected by EMP.

 

[AlienALX]

I thought you were going to say the above about valves colouring the sound.

Why not go the whole way and build a valve power amp too.

On another subject one of the funniest uses of valves I came across was when the USA first got their hands on a Mig 25 fighter jet, it was full of valves instead of transistors.

At first the Americans had a real good laugh at the Soviet Unions top fighter jet using such ancient technology, then they crapped themselves when they realised that valves are not effected by EMP.

Put simply - money. Valve amps are not very expensive at the low end, but as soon as you start trying to make some guts you need lots of valves and big ones at that.

I originally bought a Little Dot MK1. This is basically valve pre and a transistor power amp. I loved it, best sounding amp I'd ever had because it was perfect for me. Buckets of power, too. Well after about six months the left channel failed. If you rocked the valve it worked again, and I hobbled on for a few months doing that from time to time. Obviously it was poor soldering. Eventually I sent it back and got a LD MK2, which is valve pre (the same as the LD1) but valve power too. These were quite large valves..

The first one that came got sent back because I genuinely thought it was buggered. The sound output was very low, not even a third of the output of the LD1 and in the end I realised it was because it was all valves.

I have a Graham Slee Entheos Novo. Very expensive amp (this is the one built by GS himself, not the half price kit). It's a fantastic amp. No colouring whatsoever and rated among the best headphone amps in the UK. Just one problem, it's not valve.

Sooo, basically I ended up using the LD2 as a pre amp into the GS and all was good again. Then the LD2 fookin packed up as well, same bloody fault.

So this time I am going to solder/make it myself. That way I know it uses quality solder and the solders are good, instead of some poor btard out in the far east being given like 2 pence per amp they build so rushing and using little solder.

And with any luck I will be back to where I was

 

[evilcorp]

That looks like a fun project and a good night's work putting it together. I like little projects like that and then tinkering with them when they are built. I will take a look at the schematic
It's good to see other hifi enthusiasts about. Hifi valve power amps are very expensive and repairs can cost a fortune. We have had the quad mono blocks in for repair 3 times in two years now. I was looking at the graham slee headphone amps for a turntable and night tme listening. I will be interested seeing how the project progresses

 

[Kaapstad]

Put simply - money. Valve amps are not very expensive at the low end, but as soon as you start trying to make some guts you need lots of valves and big ones at that.

I originally bought a Little Dot MK1. This is basically valve pre and a transistor power amp. I loved it, best sounding amp I'd ever had because it was perfect for me. Buckets of power, too. Well after about six months the left channel failed. If you rocked the valve it worked again, and I hobbled on for a few months doing that from time to time. Obviously it was poor soldering. Eventually I sent it back and got a LD MK2, which is valve pre (the same as the LD1) but valve power too. These were quite large valves..

The first one that came got sent back because I genuinely thought it was buggered. The sound output was very low, not even a third of the output of the LD1 and in the end I realised it was because it was all valves.

I have a Graham Slee Entheos Novo. Very expensive amp (this is the one built by GS himself, not the half price kit). It's a fantastic amp. No colouring whatsoever and rated among the best headphone amps in the UK. Just one problem, it's not valve.

Sooo, basically I ended up using the LD2 as a pre amp into the GS and all was good again. Then the LD2 fookin packed up as well, same bloody fault.

So this time I am going to solder/make it myself. That way I know it uses quality solder and the solders are good, instead of some poor btard out in the far east being given like 2 pence per amp they build so rushing and using little solder.

And with any luck I will be back to where I was

I remember from my Hi Fi days valve amps being very very very expensive but very good.

That looks like a fun project and a good night's work putting it together. I like little projects like that and then tinkering with them when they are built. I will take a look at the schematic
It's good to see other hifi enthusiasts about. Hifi valve power amps are very expensive and repairs can cost a fortune. We have had the quad mono blocks in for repair 3 times in two years now. I was looking at the graham slee headphone amps for a turntable and night tme listening. I will be interested seeing how the project progresses

I wish I still had my Linn Sondek setup from the early 80s, that setup could put anything digital to shame.

 

[AlienALX]

OK so I started out early this morning. I've kinda been knocked for six by my uncle having cancer, and yesterday he was given a couple of weeks if he's lucky and moved to a hospital 50 miles away. It would also seem that this had filtered down to me IDing components, because I had IDed two different types of resistor under the same label. And I had already soldered two onto the PCB before realising. DOH.

Any way, I tackled it resistors first. Then LEDs then the fixings (sockets etc)

Then soldered in all of the capacitors.

TBH most of the day got taken by making the power cable for the PSU. The PSU was not labelled for polarity so I had to basically take the plug apart to figure out which was positive and negative. Then I tried (and failed) at a few different types of braiding before settling for this.

Which will go with the theme beautifully. I ain't gonna lie, that ate up hours and hours there. Any way, with that done and sorted it was time to set it up.

Phone - pre - amp - headphones. It seems to work perfectly, so I will order some better valves soon and move onto the shell itself.

 

[AlienALX]

OK so I hooked it up to my Graham Slee last night (Once I was sure it was all working as it should) and have been running it in and listening to it since then. It's fantastic. Set all of my EQs flat and the mid range has sprung to life. I've set it very low, but enough so that the sound slider in Windows is enough to blow your ears out. Which is really cool, because recording volumes is all over the place on CDs so you usually find one is quiet and you can't get it to decent volumes.

So yeah, it's basically done all that I wanted it to do. The box and frame is a bit of a monkey puzzle, so right now I am figuring out the best way to tackle it I might talk to a mate of mine who has a lazer cutter and get it cut in black acryl so I don't have to paint/cover it.

Will see. Need to order some contact adhesive for the veneer, will order that over the next couple of days.

 

[Excalabur50]

I remember from my Hi Fi days valve amps being very very very expensive but very good.







I wish I still had my Linn Sondek setup from the early 80s, that setup could put anything digital to shame.

I had a Mauritian mate in the 80's whose brother owned a Linn Sondek it was awesome we could here it clearly 300 meters away down the street and the clarity too just wow

 

[AlienALX]

Yeah I have heard a lot of Linn stuff. For three years back in the 90s I worked for Rogers

http://www.markhennessy.co.uk/rogers/

Making the speakers on that link ^ for the BBC and collectors with lots of cash haha. We used to have all sorts of other stuff there for testing etc.



That was my setup back in around 1998. I had a Rogers E40A valve amp running my mids and highs and a Soundmaster VZ running at 2ohms for about 2000w into a Cerwin Vega Stroker 18" in a B36 Intense! cabinet.

The amp (better pics)

That was an expensive amp. About *cough* six *cough* grand IIRC. It was one of my parting gifts when the place closed down and moved to Japan. The Japs always had a really keen interest in british audio gear, so buying Rogers was high on their list of priorities. TBH I think some billionaire just decided he wanted to buy the LS35A cheaper so bought the factory lmao.

BTW guys already hawking my next project..

See this?

http://theproaudiowebblog.com/beyerdynamic-a2-review.html

Well look at the price. Then add a little soy sauce and....

http://www.ebay.co.uk/itm/HiFi-A2-P...Y-Kit-Refer-Beyerdynamic-A2-AMP-/272340072534

And I think I gots my next project. You can even get the DAC board for it.

http://www.ebay.co.uk/itm/HiFi-PCM2...store&ssPageName=STORE:HTMLBUILDER:SIMPLEITEM

 

[AlienALX]

Update. So I have been humming and harring about what to do with the shell. It's quite odd as it goes together like a jigsaw puzzle. If I plastic welded it (the mid section) then I would never be able to get it off to put a finish on it. You can't plastic weld painted edges, so I had to come up with a plan. I plastic welded the front to the two sides in the end, and the back still slots in. This brought its own problems though, I had to basically cover the front and two sides as one piece after sanding any sticking out edges smooth.

The back is its own entity and I decided to go with brushed black for the front, back and sides (so the mid section).

I am waiting on glue so that I can put the veneer on the top. I have a few small parts to paint black too, so I will get those all lined up to be done together.

The top and bottom each have four bolt holes that go into brass posts. They are like motherboard posts, but they are M3. So I have ordered 10 gold bolts from China (£2.80 for 10)

And of course it needs some feet, because when you put the bolts in it then sits on them and I don't want it scratching my desk.

They are very small and perfect for the project. I was going for the art deco look any way, and there are Georgian influences in art deco.

I will get some pics of the shell progress tomorrow

 

[AlienALX]

OK so here is where I am at. Firstly I have covered the sides and the back, and also veneered the top with the walnut burr.

As you can see, the feet are in. Very happy with the walnut, now I gotta hit it with a ton of clear.

 

[AlienALX]

OK been working on this every other day for the past while.. It's been a test of patience tbh. The veneer was full of pin sized holes (you can't really see it unless you shine light through it) and the clear was producing bubbles when painted on. So I have had to give it about seven coats and do some sanding. Problem is the surface of the veneer is not straight it's very bumpy and wavy, so it caused flat spots in the clear. It's not perfect but I am happy enough with it. It will have a decal etc on any way, so the worst will not be visible.

Today I painted the inner valve holes black. Still got to paint the outer edge black.

Won't go into the final design, but it's a bit complicated and will take me a few days yet at least. The gold bolts have not arrived yet, so I could not assemble it any way.

 

[AlienALX]

Ahh, the beauty of side quests eh? I bet you all thought I'd given up on this.. I actually put about another five man hours into it but did not take any pics. Any way, the top was lacquered and sanded back about five times. The burr is full of tiny pin holes, and they each spit out a bubble when you start the lacquering process. As such it required a shed load of work, just for a small piece ! but detail is king.

Any way, months ago I ordered some gold leaf sheet with adhesive back. It is kinda like vinyl, but it's stiffer and more brittle. Here is what I got.

That is just the top. I also did a lot of edge painting/feathering today also for the other parts. All that is left to do now is wait for the two coats of lacquer to fully harden, then cover the inside of the top with gold, then assemble.

But yeah, it's still in progress

 

[AngryGoldfish]

As a guitarist, I only go tube.

 

[NeverBackDown]

As a guitarist, I only go tube.

Why is that?

 

[AlienALX]

As a guitarist, I only go tube.

There's just something incredibly captivating about valves. I've been hooked since I was about 14. I was given an old stereo/gramophone thing and it was toast, all apart from the amplifier unit. I rescued that, re-soldered and cleaned it all up and then used it with my record deck for years (it was phono stage only)

 

[AngryGoldfish]

There's just something incredibly captivating about valves. I've been hooked since I was about 14. I was given an old stereo/gramophone thing and it was toast, all apart from the amplifier unit. I rescued that, re-soldered and cleaned it all up and then used it with my record deck for years (it was phono stage only)

That's how most boutique builders who sell their amps for £2000 started; tinkering with old radios and stuff.

Why is that?

It sounds and feels so much better. Digital and solid state technology has improved enormously over the years—to the point where professional touring musicians are willing to let go of their 30kg 50-year-old Marshall valve heads in favour of the convenient lunchbox modelling device—but the way the harmonics of an instrument works with vacuum tube amps, that's what makes them so desirable. Some call it snobbery and unicorn urine, but that's complete BS in my opinion. While I can't tell the difference between a £2000 digital amp modelling a £2000 tube amp in a heavily compressed YouTube demo, I can tell the difference in real life, where it actually matters. The way the amp reacts with your playing is where it counts. An audience of a few thousand wouldn't be able to tell the difference, but you the musician would.