Post your Solid State pics here.

[sakis]

re sy fotios .... skip the diy for a few hours ... its easter time ... good oldfashioned arnaki is waiting for you in afew days ...

gongrats on your project ... com to think about it only a few from you the Dirty Harry and now the pro .... still i belive that are simply one of the best i ve seen together with support and documentation

best regards my friend ... diy audio at its best ...yet again proud to be a member .....

[fotios]

Originally Posted by sakis

re sy fotios .... skip the diy for a few hours ... its easter time ... good oldfashioned arnaki is waiting for you in afew days ...

gongrats on your project ... com to think about it only a few from you the Dirty Harry and now the pro .... still i belive that are simply one of the best i ve seen together with support and documentation

best regards my friend ... diy audio at its best ...yet again proud to be a member .....

Hi Sakis
Thanks friend for your kind words and above all for your wishes . We are faced with a "mountain" of problems (all people knows) but the EASTER is "EASTER" here in Greece. These HOLY DAYS are unique for us, so we forget everything else.
Well Sakis, happy easter and "Kali Anastasi" to you and to your family. Give "φιλακια" (= kisses) from me to your baby (is son or daughter?) and to your wife Maria.
Fotis

[kct]

Originally Posted by fotios

Hmmm... So, is a custom made motorized encoder machined in a CNC milling machine. However, is a masterpiece of mechanical process. I like it very much, especially the ball bearing base .
I had in my mind a different approach (based on my preference of the absolute isolation of the analog and digital part) which i will realize when i will have money left over . My idea is the use of a stepper motor to drive a "Gold Point" (or something like this) rotary attenuator. I don't have problem with ALPS motorized pots, except that i prefer 1 - 2 KOhm track resistance which is not offered on the market.
BTW, the frame of my MTB (a 12 years old "GT Pantera") is made from 6061 aluminum tubes, is this alloy good?
Happy Easter to all

@fotios
Thanks for your complements, I knew there are still some fellows out there who appreciate the mechanical part of this operation. The initial design of the HPA 1.0 by gmarsh had a pot in it. However the pot was used with an AD input on the MCU to control the digital attenuation in the audio DA chip. So I had to modify the code quite a bit for the encoder to work with it. Before I went ahead and had the machining work done, I had considered using an ALPS motor assembly, but it was just to big to fit the case.
Yes, not only I went for custom made volume control but what about custom made 4 layer boards, custom front and rear panels with custom anodize and laser job, custom AR glass coating ?
Soja, please don't ask how much I spend on this as it may not seem justifiable and could be considered a money pit but owning a decent performing and looking unit is priceless to me.

If you ever follow up on the 'Gold Point' thing you have in mind, you may want to check out Mil-Max spring loaded gold contacts. Perhaps design a small gold plated PCB with round pads arranged in an arc...

Well, I am not an alloy expert so it depends on the application. 6061 is a very common alloy with universal application. I preferred the 7075 alloy over the 6061 as it machines better. 6061 is 'soft' when compared with 7075 if I am not mistaken.

Your volume controller looks very nice too. Altho if I may suggest, you may want to calibrate to dB instead of percent. I see you prefer through hole components over the SMD stuff. I like TH as it solders easier and simplifies routing, unfortunately I had not such luxury with my project.

Here are some display options my amp cycles through before showing the VU meter bar graph.

Cheers

[fotios]

I saw your photo gallery. Very nice work, I like very much compact designs and so i can perceive the reason you don't use ALPS analog volume control.
Your ideas are very good. I have to admit that same ideas have passed many times from my mind. I like the... extreme diy . You could see, for example, that the double sided PCBs of my control unit are home made (for this reason the thru holes). I have some tools in home - like a mitre saw and a hand operated milling table - so most times i make the aluminum cases of my projects by alone .
Being busy - and tired - with pro audio equipments for more than 20 years, i know very well the usefulness of dB unit in adjusting the signal level on mixing desks, electronic x-overs, compressor/limiters etc. For home use, i consider dBs unnecessary because the acoustic power of Hi-Fi speakers is relatively small (usually 110dB SPL max compared to the 130-135 dB SPL max obtained from many PA speakers). So, I consider sufficient the volume expression in percentage.
Fotis

[apexaudio]

APEX NX14

[fotios]

Here are some pics from the last work that we did with Lineup. The very polite and kind Lineup helped me a lot in the design of this Preamplifier. Thanks to the extensive use of simulator, we have obtained a really good result. For details of circuitry and measurements, please look at Preamplifier from Lineup & Fotios for fun
and at Phono preamplifier from Lineup & Fotios. In general, it is an Active Preamplifier included in the same case with a Phono Stage, both implemented with discrete devices and high quality parts. It offers 4 inputs: PHONO - CD - DVD - LINE. Its gain is unit (Av = 1) and offers both Single and Balanced outputs. A Record Output is also included, and thanks to the use of robust transistors in the output of main buffer (either MJE172-182 or BD139-140 mounted on heatsinks) the Preamplifier has the ability to drive low loads like a pair of headphones. It is remotely / manually controlled by my Control Unit described previously.

[kct]

@fotios

You have great skill, the unit you build looks very professional. I checkout the other thread, this is beautiful stuff you doing there. Makes me want to do something like that too... You do have a great advantage of working in the audio industry.

@apexaudio
You also have put together a nice Amplifier.

DIYAUDIO forever

[dudaindc]

Originally Posted by fotios

Here are some pics from the last work that we did with Lineup.
...

Awesome Fotios!

[osscar]

I agree, very good fotios.

[fotios]

Originally Posted by osscar

I agree, very good fotios.

Thanks a lot osscar you are very kind .