audio-talk

https://photos.app.goo.gl/QydA6FNRVjg2eAVw7

Finally got myself a Transporter from the guy selling them off (relatively) cheap in CA.

Thats a blast from the past.

Looks very cooooooool

andrew Ivimey wrote: ↑Mon Jan 04, 2021 9:56 pm Looks very cooooooool

Indeed. What is it ?

Does that matter?

Fules!

It's a Psychonavigator of course, it says so on the front dunnit innit.

Very cooooool SB, nice one Tony.

Yes, you can't say I'm not bang up to date with tech...(err, yes you can)

It's the Squeezebox's big brother. The manual still refers to the "Slimserver", which shows how old it is. Brand new boxed though, never been used. Apparently these ones don't have the "twiddle knob" (my description not theirs) on the front because they ran out of parts and only had the bits to make the "SE" version where they blanked off the hole instead.

I've always wanted one of these but not at the price they originally went for. I will do a proper A/B test against my 1541 based creation (which contains a Squeezebox Duet, reclocker and I2S into 1541 with the Hawk Audio output stage) and see who wins.

Well, I've had chance to let the Transporter "run in" for a few days and have done some listening tests with speakers and with WAD HD83/HD600 headphones and although the Transporter is very good, it is not as good as my home-brewed DAC based on the Pedja Rogic 1541.

I was in one way hoping it would be better but then again I spent a _lot_ of time and money on my custom DAC so that would've been a shock if it won the battle!

The sound from the Transporter has that modern DAC feel to it which although obviously accurate and perfectly fine it just doesn't have the open/spacey feel of the 1541. I can't really describe it, just a more airy realistic feel.

I did go way overboard on my DAC though with separate transformers and super regs for each part, plus it has a (probably) S2 1541A chip, which, even when I got it years ago were very rare.

So the transporter will do 2nd system/headphone duty and will not be replacing my main DAC just yet! (Unless it fails, it _has_ been in constant use for well over a decade!)

In its day, the transporter was improved by the mods that ModWright did for it.

https://6moons.com/audioreviews/modwrig ... orter.html

Thanks for that link Nick. So they're upgrading the output stage, which could be a nice project for me too. I'd probably try to go solid state though, rather than valves.

Yep, it was the ModWrite Transporter that made me use the AK dac with a valve output stage in the dac I made.

Wow, ok, then if the Transporter has that much promise then perhaps I should get cracking on it!

So would you recommend going the valve route rather than semiconductors? There's not a lot of room in that case and heat could be an issue as I've read that most Transporters fail due to the SMPS (for the display/processor part) capacitors.

Well, I went valve, YMMV. I don't know what impact the rectifier and two dual triodes had on ModWright reliability. I updated a couple for Dan many years ago from V1 to v2 to avoid them going back to the US, but I don't know what the circuit was. I do know that v2 involved adding a couple of depletion mosfets. I suspect knowing the other ModWright stuff it would have been a kimmel mu follower or similar.

Interesting stuff that write-up on the Kimmel mu follower. Lots of food for thought...

As an aside, I wondered whether Hawk Audio still had any pcbs for the output stage which I could build. A bit of digging on the web and it turns out John van der Sluis, the Hawk Audio guy died in 2017. I've been out of this audio DIY game for so long the entire landscape has changed.

I guess I could still build the same circuit as I have the original cct and parts list (somewhere!) but the pcb was quite complicated so probably not worth the effort. The circuit was a derivation of their A18 power amp and can be seen in this article from a long, long time ago!:

https://www.tnt-audio.com/sorgenti/hawkmpdac_e.html

So then I looked up Pedja Rogic and it seems he is still going strong but it seems he's now more into built DACs rather than DIY kits. I guess the world has moved on?

By the way, does anyone know if Leo from Nottingham is on this forum or where I might get in touch with him? It was Leo who got me into the 1541 chip and Pedja's DAC implementation. I have an email address for him and pinged it but no response yet,

Cheers,
Tony

Nick wrote: ↑Sat Jan 09, 2021 1:35 pm Yep, it was the ModWrite Transporter that made me use the AK dac with a valve output stage in the dac I made.

You’re welcome Nick