DIY audio: what are you building?

[mwhouston]

39 minutes ago, F18 said:

Looks good for a small footprint phono preamp.

I’ll assume we are taking about the same thing. It’s a 180Wpc Class D power amp. 

[F18]

8 minutes ago, mwhouston said:

I’ll assume we are taking about the same thing. It’s a 180Wpc Class D power amp. 

 

I meant the case. It has a small sized footprint for a phono preamp I have in mind. Can the top metal plate support heavy iron?

[mwhouston]

 Very light Al. Nothing too heavy. You could add another plate underneath. 

[mwhouston]

I was looking for one more DIY project to round out my Wood Cheeks series (see examples below). How about a hybrid tube/OPAMP headphone amp. 

 

Here is the cct. brd. for the PS with choked (sits off brd.) double Pi HT supply. Three DC voltages; heaters, HT and OPAMP voltage. A differential B+ splinter will be built on the OPAMP brd. to power the chip.  

Edited April 30, 2019 by mwhouston

[RCAJack]

I think I've found a case for my (ultra long term) preamp project.

• 211.5mm wide; 150mm tall; 311mm deep
• All alloy panels 3mm thick; front panel 8mm thick; weighs ~3kg
• Lots of ventilation slots
• ~$125 shipped including GST

https://www.aliexpress.com/item/NO-1multi-use-full-aluminum-chassis-with-radiating-hole/1964442115.html


The thing that caught my attention is that the seller says: "We can drill the holes as your requirement. The simple holes are for free, the complicated holes are charged according to the situations. Please send your hole pattern to our mailbox"

 

So at some point I'll shoot them an email to see what they need. Meanwhile, I'll have to learn the basics of using some sort of CAD software I suppose. I wonder if they'd send me their CAD designs so I could edit in the hole sizes and positions?
 

 

[mwhouston]

Re-purposing an enclosure and PS from a failed chip amp to a new chip amp. I have bigger storage caps to add here but just checking voltage levels.

[allthumbs]

Can I ask a dumb question without notice and ill prepared, is remote controlling of DIY amps, source switching, volume control etc difficult or too expensive or signal interfering or just tradition not to be included?

 

Mark, the Mongrel Audio triode headphone amp is a joy and is my bedroom set up, sweet.

Cheers

Carl

[mwhouston]

I have two remote control volume pots but have never bothered to put them in. No real reason just staying a little retro.  

[Batty]

New pre amp on the cards for me, another GB on DIYAudio.

Yarra Pre with Melbourne cards inside about 16dB gain.

The unity gain B1 is not enough to drive the M2X to full power.

[mwhouston]

6 minutes ago, Batty said:

New pre amp on the cards for me, another GB on DIYAudio.

Yarra Pre with Melbourne cards inside about 16dB gain.

The unity gain B1 is not enough to drive the M2X to full power.

I’ve built two B1 and always thought they sounded better than the BoZs but yes I can understand there may not be enough gain to fully drive some amps. 

 

You could put a single stage tube preamp upfront and use the B1 as a buffer. 

Edited May 11, 2019 by mwhouston

[Batty]

Input for max power on the M2X is 2,75 volts, CD is only 2v.

 

I bought a Oatley valve HP amp and thinking of configuring that as a gain stage.

Edited May 11, 2019 by Batty

[Batty]

I just put the Retro Oatley between Phono and Pre, now I can use my TT.

Still needs a few more dB gain to get to full potential.

[mwhouston]

It lives. Re-purposed old chip amp enclosure (1U) and PS now with Audio Sector module assembled many years ago. 35-0-35V on the module with some over-kill trannies and power filter. 

 

Sounds crisp and punchy. The chip is the Overture which has two 3886 in it. This amp is to go in the TV area with 12” Beyma concentrics (96db sensitive) and subwoofer (175W) and electronic Xover. 

[Batty]

I like big transformers. Just a baby 360VA.

 

[mwhouston]

With lid on.  Should add 2.5mV (RMS) of noise under worse case conditions. Low for a power amp. Should produce about 60W.

Edited May 11, 2019 by mwhouston

[WINEDS]

On 11/05/2019 at 12:03 PM, Batty said:

New pre amp on the cards for me, another GB on DIYAudio.

Yarra Pre with Melbourne cards inside about 16dB gain.

The unity gain B1 is not enough to drive the M2X to full power.

You could also consider the Salas DCG3 or DIY Nutube both of which I have built for the same purpose.

[Batty]

Yes, looking at the Nutube too.

[betocool]

On 11/05/2019 at 12:09 PM, mwhouston said:

With lid on.  Should add 2.5mV (RMS) of noise under worse case conditions. Low for a power amp. Should produce about 60W.

That cute roundy thing on the right... what sort of source is it?

 

Cheers,

 

Alberto

[mwhouston]

40 minutes ago, betocool said:

That cute roundy thing on the right... what sort of source is it?

 

Cheers,

 

Alberto

A crude CD player I got for nothing when signed up for a years subscription to Time magazine 25 years ago. It’s only my test source and the small Tandy speakers also part of the test setup. Thought the speakers now have a proper Xover and magnesium/Al 4” woofer mids. 

 

Just my standard test setup. The CD player also has line out and runs on batteries (as here) or external plug pack. OK as a freebie. 

[betocool]

1 hour ago, mwhouston said:

A crude CD player I got for nothing when signed up for a years subscription to Time magazine 25 years ago. It’s only my test source and the small Tandy speakers also part of the test setup. Thought the speakers now have a proper Xover and magnesium/Al 4” woofer mids. 

 

Just my standard test setup. The CD player also has line out and runs on batteries (as here) or external plug pack. OK as a freebie. 

I was messin' with you a bit. In my youth I owned a number of those, good for long trips on the bus or planes. Hadn't seen one in years! I've had Sony, Aiwa, Cheapo, Panasonic I think? They had this acronym for non-jumping players... ESP technology?

 

Cheers,

 

Alberto

[bob_m_54]

15 hours ago, betocool said:

I was messin' with you a bit. In my youth I owned a number of those, good for long trips on the bus or planes. Hadn't seen one in years! I've had Sony, Aiwa, Cheapo, Panasonic I think? They had this acronym for non-jumping players... ESP technology?

 

Cheers,

 

Alberto

Yes, I remember having one of those velcro'd to the console in the old Toyota Camry. ESP (Sony) = Electronic Shock Protection, which was basically a bigger memory buffer.

[mwhouston]

Assembled not wired. The seventh in the “Wood Cheek” series. Two sold still have five (now). This one is a hybrid headphone amp. Tube front end and OPAMP (think CMoy style) back end. Two inputs on the rear.

 

The front end is a 4SU type meaning any 12A?7 can be plugged in with no tweaking of passives. A tube rollers delight. External DC supply driven by a 24VAC wall wart. 

Edited May 15, 2019 by mwhouston

[betocool]

The Cmoy, that's the one in the Altoids can? I have a similar build with 2x NE5534 in parallel and it sounds superb.

 

Cheers,

 

Alberto

[mwhouston]

Can I convince any other tube amp builder out there in DIYLand to have a go at a wine box tube amp. External Tranni box  allows you to build a few with their own unique PS internally but use the same Tranni box. 

 

The tranni box box is two 12V 300VA Trannies back to back to produce 250VAC and 12VAC for the two 6V filaments (in series). 

 

Take another look at mine. Happy to help anyone who wants to have a go. Think about it you can use up a few of those tubes which have sat around for years and any other odd parts not getting use. The box is $9 from Dan’s.

[A J]

Can I convince any other tube amp builder out there in DIYLand to have a go at a wine box tube amp. External Tranni box  allows you to build a few with their own unique PS internally but use the same Tranni box. 
 
The tranni box box is two 12V 300VA Trannies back to back to produce 250VAC and 12VAC for the two 6V filaments (in series). 
 
Take another look at mine. Happy to help anyone who wants to have a go. Think about it you can use up a few of those tubes which have sat around for years and any other odd parts not getting use. The box is $9 from Dan’s.

I would be keen to have a look ? What tubes does it use ?
AJ