A DIY Pre-Amp Kit
Here are the basic at the moment idea we have.
![image](https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xta1/v/t1.0-9/12644900_1552287921756233_7846254403858296064_n.jpg?oh=30748ee96459852c3a0249db76dcc4a1&oe=572C5934)
![image](https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xtp1/v/t1.0-9/12662684_1552290741755951_3019651205296477733_n.jpg?oh=23e2b7473ecc1ffed301c4fb850c71cd&oe=576FFEE2)
![image](https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xlp1/t31.0-8/s960x960/12672054_1552290725089286_79255403842301514_o.jpg)
MM,MC, MP3(special filter), CD, Pre Out and SECA Headphones, very similar to the one Alan Brown heard at TQ.
It is filled with SMD and the photos are the one Alan E. has used. and is using now.
![image](https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xta1/v/t1.0-9/12644900_1552287921756233_7846254403858296064_n.jpg?oh=30748ee96459852c3a0249db76dcc4a1&oe=572C5934)
PSU Board
![image](https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xtp1/v/t1.0-9/12662684_1552290741755951_3019651205296477733_n.jpg?oh=23e2b7473ecc1ffed301c4fb850c71cd&oe=576FFEE2)
Pre-Amp PCB
![image](https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xlp1/t31.0-8/s960x960/12672054_1552290725089286_79255403842301514_o.jpg)
As will see it has two pre-outs and two HP (SECA) outputs these can be set for up to 5W/ch so be warned.
The PSU can be run in Standby and have a small press to make switch to operate it.
Ribbon cable was used to connect the power to the pre.
Circuits and BOM to follow.
Also note the space behind the volume pot this will accommodate a IR Remote RX later, for the arm chair DIYers. (a contradiction of terms).
The MP3 uses a twin filter to emphasize the high frequency and the reduce them with correct phases and produce a much better sound the BW is held tight and flat 20Hz - 20KHz thus reducing clock crap and other unwanted signals.
Comments
That's an interesting idea on the "mp3 in" circuit but I'm thinking, how many people would actually use mp3, in anger, on a decent system? Genuine question BTW, please give views there anyone.
Love the two pre-outs but personally would have no use of the headphone section, which leads me to the next thought.
Why not make the sections fully modular (as far as layout benefits/concerns allow), builders could then select only what they need. This could lead to more actual builders taking the leap, with the possibility of adding other sections later if needs change?
Just throwing out thoughts here, like a stone in the proverbial pond, let's see what the ripples bring
I'm off to read up on the MUSES Volume Control now...Shaun, how good compared to the likes of DACT (I currently use a Khozmo 50Hz stepped shunt attenuator in my existing DIY pre).
I'll go with the flow, honestly. I know it will be awesome. Put me down for one.
I will practice my 'flat toe' exercises for the SMD soldering, as you recommended a long while ago...
Be seeing you in a few weeks, I got a bundle of scrap from Dave for you to take a look at.
:-\"
Modular makes sense.
Yes more expensive but spread over time collecting the different modules the cost becomes instalments so easier in some ways to afford. IMHO It allows for a staggered realise approach which can help
BTW
I've never built to save cash and only for the pleasure it brings (like most DIYers). For example my Paradise phono stage/Calvin Buffer probably cost me around £500 to build (not cheap) but it sounds superb and as far as I know is not available commercially at any price. Joachim Gerhard (Audio Physics) designed it from scratch in what seemed to be a 2000 post brain storm over on DIYA.
It’s expensive but good (read very good) and IMHO cash well spent.
I also have another 3 Phono Stages in rotation.
‘’A change is as good as a rest’’
A pre without HA/PHONO is more of a catch all as it can also be used by the Digital brigade (I have DAC'S and phono stages) but it's going to be hard to persuade someone with Digital only to invest the time and cash building the phono stage no matter how good. (And no matter what we may think of digital replay it’s not going away any time soon)
That's my general feeling but I'm still interested enough to build one but I’d rather pay a little more and have the modules.
But some specs are coming so let's see.
Just a few thoughts.
Heads Up
BTW anyone looking for a 180g Blue Note John Coltrane - Blue train? Don’t Laugh but I picked one up in Sainsbury’s. Di Agostini presents Classic Jazz with free mag. I nearly fainted as my copy is getting a little over played so a replacement at that price was welcome and more to follow.
Yup £9.99 woooo
Thanks Paul
Great stuff Colin
I was finking... how far beyond a numpty like me is it to build the above? I appreciate that the SMD stuff is small and a challenge, and probably help would be needed with an order list of components. But, the tooling is already made for this board, no? As is a prepared BOM?
Could DIYers put this one together?
Or pay for a populated board sans chassis & transformer?
Like I said, just thinking aloud mate, happy to be corrected/shot down in flames as required.
Great to see these being taken up. :-)
Really looking forward to seeing how you guys get on with things.
B-)
I did actually post a few pics in the Solid state section over on diyaudio but didn't get much of a response.
Maybe a build thread would have been better; they don't no what they are missing.
Colin started a thread some time ago over on DIY Audio, but not much interest.
http://www.diyaudio.com/forums/solid-state/275291-seca-kit-colin-wonfor.html