Amp Camp Amp - ACA

[Variac]

Sooo sorry I went off topic.. Bad Variac...

Turns out that a search turns up lots of people on the task. A few..

http://www.diyaudio.com/forums/digital-source/201364-raspberry-pi-new-diyers-digital-hub.html

http://www.diyaudio.com/forums/digital-source/222451-digital-music-server-without-pc.html

 

[nicoch58]

It's the way to get started, and most people are also startled at how great it sounds. If you do end up making other amps then it might become surplus, but then it 's still very useful for a table top system, computer system, bedroom system, present to GF, present to your dad..

Variac brilliant too

 

[gmoore3181]

Well Mark - that's a whole 'nother thread.

 

[waam68]

Little help needed

Hi guys
I finished wiring up the second monobloc. I'm getting a low grumbly distortion on that channel with no signal but the preamp connected. I happened to brush the case of that channel into the other working monobloc and the bad channel suddenly went dead quiet so I'm guessing earthing? Can anyone give me a steer on the most likely place to start?
Thanks
Mike

 

[Zen Mod]

it's hard without pictures to see what you're doing

 

[merlot5nils]

O.k. - I will build it.

1. Can You counsel me a suitable Pre-Amp? Maybe also DIY?

(Not to much expensive / A phono-pre could be fine - but it's not a must.)

2. And what do you think about passive pre's? Less parts = better sound?

 

[nicoch58]

Nelson Pass B1 of course


http://www.passdiy.com/store.htm
http://www.diyaudio.com/store/amplifier-circuit-boards/mezmerize-b1-buffer.html

 

[nicoch58]

phono Simplistic NJFET RIAA - Page 846 - diyAudio

passive optivol http://www.ska-audio.com/diy/optivol.html

 

[merlot5nils]

Thank You! What's written about the B1 sounds very interesting.

But for me as a beginner it seem to be difficult? What I like in the CAMP AMP: All parts are complete (kit), it's described very well including pictures.

At the DIY-Store is onle the PCB available. And I found a large list of parts needed - some very simple with number, other with "your choice". I'm cunfused.

Is there a source where to buy a complete kit of the B1? (As simple as the CAMP AMP?)

 

[nicoch58]

sure ? look there

not much stuff









DIY Order Form

 

[Zen Mod]

sure ? look there ....

and here : FIRST WATT B1

all info you need

 

[merlot5nils]

Thank You! The B1 on your pictures looks simple. Very fine.

But the B1-PCB & parts-list as offered in the DIY-store looks completely different. So I'm confused.

Where can I buy a simple B1-kit as seen on the photo & firstwatt.com?

I guess, there exists no kit - only a PCB?

Is it the one offerd here: DIY Order Form ???

I should buy the one with 4 matched JFETS and organize all other parts by myself? True?

 

[Variac]

I believe Papa Pass refers to the JFET at the line input on the ACA as a Buffer, so you already have one, albeit simpler. The ACA is actually a pretty complete little amp! I believe that most sources can drive it to clipping so a preamp might not do much. Passive would be the first thing to try.


B1-
Yeah If they are still selling it that B1 board form the PassDIY site is the original and simpler one and getting the included 4 matched JFETS is a huge convenience
Then order the remaining parts from a place like Digi-Key Mouser, Allied.....

The board offered at the store has an integrated shunt power supply instead of a wall wort, relay based input switching, and a place for a volume pot. That's why it looks a bit more complicated


mark

 

[ndmrslp]

I read the diyaudio newsletter featuring the amp camp on the same day that my old carver amp decided to stop working yet again. After reading about the event and the amp I've decided that it will be my first diy audio project

My first choice would be to purchase the complete kit, but it is currently sold out. Since I'm without an amp at the moment, I'd prefer not to wait for the kits to restock. To that end I'm putting together a list of everything I need to buy for the project, and of course I have a few noob questions:

1. One item on the parts list (.68 ohm, 3w resistor) is out of stock at Digi-Key and I don't see an obvious replacement or other source for it. Any advice other than waiting?

2. I'm slightly confused by the info for Q4 on the parts list. As mentioned by LBHajdu, I see two versions of the 2SK170 (GRF and BLF) in stock at Mouser, but I don't know which one is correct or if it makes a difference. The article mentions LSK170 as a replacement. Are these available online?

3. Is there a parts list somewhere for non-pcb stuff like wire, switches, binding posts, etc? I see the heat sinks, pcbs and power supplies in the store, but other than that I'm not sure. I suppose those things may be obvious/on-hand to diy veterans

Thanks and sorry for the long first post...

 

[merlot5nils]

Since I'm without an amp at the moment, I'd prefer not to wait for the kits to restock.

Hi, the customer-service of DIY-store wrote me on October 31 "The Amp Camp Kit will be available in-store very soon. Check back at the store within the next 7 days."

So maybe it makes sense to wait...

----

Still a question: THESE 5W-AMP CAN DRIVE MY RIPOLS-SUB? For sure it's enough for the OB's, but will there be bass? (I don't want to make "disco", but my listening room has arround 30 squaremeters.)

By the way: Yesterday a friend brought his QUAD II tube-amps along, together with a good preamp. I was amazed how much better it sounds than my MUSICAL FIDELITY A1!!! Much more clearity and the bass was even cleaner.

 

[Zen Mod]

...
Still a question: THESE 5W-AMP CAN DRIVE MY RIPOLS-SUB........

how can we know that ?

all we know is that you're driving them with A1

 

[Variac]

It will be more like a month before there are more kits..

Hi, the customer-service of DIY-store wrote me on October 31 "The Amp Camp Kit will be available in-store very soon. Check back at the store within the next 7 days."

So maybe it makes sense to wait...

----

Still a question: THESE 5W-AMP CAN DRIVE MY RIPOLS-SUB? For sure it's enough for the OB's, but will there be bass? (I don't want to make "disco", but my listening room has arround 30 squaremeters.)

By the way: Yesterday a friend brought his QUAD II tube-amps along, together with a good preamp. I was amazed how much better it sounds than my MUSICAL FIDELITY A1!!! Much more clearity and the bass was even cleaner.

 

[bnorrish]

I was goiing to buy the kit but bought the PCBs and heatsinks as it was sold out. I ordered all the electronic parts from DigiKey and Mouser from the provided build list. What it be possible to list the non-electronic parts as well? Thanks.

 

[LBHajdu]

2. I'm slightly confused by the info for Q4 on the parts list. As mentioned by LBHajdu, I see two versions of the 2SK170 (GRF and BLF) in stock at Mouser, but I don't know which one is correct or if it makes a difference. The article mentions LSK170 as a replacement. Are these available online?

The difference is the IDSS. M.P. says in the B1 project:

The Idss is simply the current that flows through the JFET when the Gate and Source are grounded and +10 volts or so is applied to the Drain. Often when you buy JFETs you can get them in Idss grades. I use GR or BL grades for this project.

The datasheet says:

GR: 2.6~6.5 mA
BL: 6.0~12 mA

I think both would work. In the amp camp project the bias of the jfet is set by the servo loop, R9 and the Vgs of the lower power mosfet. Personally if it was me I would go for BL.

LSK170 is also a good option because you are supporting a company who is actually committing to keep it in current production now (they have the same grades).

Leve

 

[Loudthud]

You want the BL grade. If Idss is below about 4.5mA, you won't be able to set the quiescent output voltage.