Amp Build Diary

[Beer of the Bass]

[quote name='Chienmortbb' timestamp='1418378067' post='2629642']

Connex Electronic are a small Chinese company that has built a very good reputation for quality and price in HiF circles. They have a few likely cndidates in their range but when I tried to order another item from them before, my order was refusd and my money refunded as I was blamed for a flame war against them started by another Brit. Connex products are distributed in Europe but none of the distributors stock the integrated modules.

[/quote]

I have a couple of Connex modules for a project that I've been meaning to get on with (not having a gigging band has made it less of a priority). I haven't wired them up yet, but they look well put together. Their response to emails can be slow (apparently this is normal when dealing directly with Chinese companies) and their documentation isn't as good as some manufacturers - for example I still don't know the input sensitivity of the power amp and I'm going to have to work it out for myself by measuring the gain. Their prices are very good though!

[Chienmortbb]

[IMG]http://i57.tinypic.com/and01l.jpg[/IMG]

[Passinwind]

[quote name='Chienmortbb' timestamp='1418378067' post='2629642']
Thanks to passinwind for keeping this thread going. My wife has picked up a post op infection and we have both had Man Flu (her words not mine).

The PCBs are superb quality and although there are cheaper suppliers, OSH Park really have a quality product.[/quote]

OSH Park works on a cooperative arrangement where you share space on a big slab and they cut out the pieces and send you your bits. This happens quite quickly (currently ~12 days from order to mailbox), and shipping is included to more or less anywhere. You do have to buy in multiples of 3 boards at a $5 per square inch flat rate. These particular boards are just about 2 1/2" x 4", so around 50 bucks for three of them. The price goes down a bit if you commit to 150 square inches total, but their thing is supporting hobbyists and prototyping for small businesses.

Happy to see some forward movement, that power amp module looks very promising. "Man flu?" Has your wife been talking with mine?

--CE

[LukeFRC]

[quote name='Chienmortbb' timestamp='1418402002' post='2629962']

[/quote] can I ask what module you went with? (specs and price would be good too! )

[Passinwind]

Second one down:

[url="http://www.class-dmodule.com/#!amplifier-modules/ccy0"]http://www.class-dmo...er-modules/ccy0[/url]

Edited December 12, 2014 by Passinwind

[Chienmortbb]

Yes I got the Boyoho MY1-251PA. Cost is £109.66 for the amp, £3.94 for the cable set and £12.62 postage form the Netherlands. So £126.22 although this can change as the £/€ exchange rate changes.

http://stores.ebay.co.uk/Class-dmodule or you can contact them by email to order.

They also do a 150/300 module at about £90 and couple of dual channel ones that can be bridged for higher outputs.

[Chienmortbb]

[quote name='Beer of the Bass' timestamp='1418382969' post='2629696']
I have a couple of Connex modules for a project that I've been meaning to get on with (not having a gigging band has made it less of a priority). I haven't wired them up yet, but they look well put together. Their response to emails can be slow (apparently this is normal when dealing directly with Chinese companies) and their documentation isn't as good as some manufacturers - for example I still don't know the input sensitivity of the power amp and I'm going to have to work it out for myself by measuring the gain. Their prices are very good though!
[/quote]The Connex modules get a really good press as I said but I was put off by my previous experience with them.I eventually went with the Boyoho MY1-251PA, mainly because of the pre sales support that I got from Michel at Smart and responses from the Boyoho factory.

As I said at the start of the thread, part of the inspiration was the 1 X 12 Cab Build. I modeled the Beyma SM212 speaker and in the proposed cabinet and tuning, the maximum SPL is achieved at about 230 watts. So 250W into 8 and 500W into 4 ohms was the target. The fact that the amp is capable of driving double the power into 4 ohms compared to 8 ohms means that the power supply is beefy enough for the task. In fact the power supply is rated at 600W. This allows a full 250W to be put into two 1x12 cabs. Compare this to say the Hartke 3500 where the power into 8 ohms is 250W but only 350W into 4 ohms. Clearly the power supply in the Hartke limits the total power output.

[Beer of the Bass]

[quote name='Chienmortbb' timestamp='1418422921' post='2630234']
Yes I got the Boyoho MY1-251PA. Cost is £109.66 for the amp, £3.94 for the cable set and £12.62 postage form the Netherlands. So £126.22 although this can change as the £/€ exchange rate changes.

[url="http://stores.ebay.co.uk/Class-dmodule"]http://stores.ebay.co.uk/Class-dmodule[/url] or you can contact them by email to order.

They also do a 150/300 module at about £90 and couple of dual channel ones that can be bridged for higher outputs.
[/quote]

That looks like a good deal, and it's nice and compact. I have the Connex SMPS800RE and the 600 watt IRS2092 power module. While having a conservatively rated power supply could be a good thing, my modules work out a fair bit larger than this integrated module so they're not going to make for as compact an amp.
If I hadn't already bought the Connex modules I'd have been considering that one, especially as they're available in Europe and have decent documentation.

[Chienmortbb]

[quote name='Beer of the Bass' timestamp='1418463754' post='2630354']


That looks like a good deal, and it's nice and compact. I have the Connex SMPS800RE and the 600 watt IRS2092 power module. While having a conservatively rated power supply could be a good thing, my modules work out a fair bit larger than this integrated module so they're not going to make for as compact an amp.
If I hadn't already bought the Connex modules I'd have been considering that one, especially as they're available in Europe and have decent documentation.
[/quote]

That supply is well know in DIY HiFi circles and has a great reputation. I don't think you will regret buying the Connex units.

[Chienmortbb]

Sorry for the delays in updating this thread but the "infection" was in fact a secondary Cancer so have the whole cycle starts again. I have made some progress and will post more with pictures soon,

[Chienmortbb]

As promised a picture of the progress so far. All boards mounted, power amp, two pre amo power supplies plus the Pre amp and HPF unpopulated PCBs.
I have used a heatsink to both support the power amo module and take more of the heat away. More about that later.

Next job is to drill the rear panel and test the PSUs with the power amp. I will then do a soak* test while building the preamp anf HPF modules.

*Soak testing is sometimes (incorrectly ) called running in I will run the moufles for 100 hours to ensure there are no infant mortality issues.

[Passinwind]

Lookin' good, real progress going on. I'm on to final wiring of my set of preamp boards, hope to be up and running by week's end. I got diverted by a quick onboard preamp build for my ancient Travis Bean, similar to the MM clone one I sent you last year.

Edited February 3, 2015 by Passinwind

[Passinwind]

[quote name='Passinwind' timestamp='1422986178' post='2679196']
Lookin' good, real progress going on. I'm on to final wiring of my set of preamp boards, hope to be up and running by week's end.[/quote]

Done, and working pretty well for such early days. Should be safe to stuff those boards now Chienmort.

[Chienmortbb]

Although the case is small it is not ultra small so I have a reasonable anout of room to work in.

I am working on the back panel, more on that later.

One of the earlier contributors told me to get all the bits together before I started, Apart from cosmetic parts like knobs I did this but that stretched me financially at the time. So I compromised on cost on one component and.,,

Below is part of the email I sent to Charlie ( passinwind) earlier today. After re-reading it I thought it was good info do I am putting it up here for info/discussion

I have tried to make sure that I don't compromise on parts but when I was a bit cash poor, I bought some unbranded jack sockets for the rear EFX send and return as well as Pre Amp out and Power Amp in.

Big mistake. The barrel is 1mm short and the plug is not held in properly, I am in the process if getting those replaced. I have been looking carefully at what jacks to use and found some interesting detail in the specs. Neutrik, Switchcraft and Cliff rate their jacks for 10,000 insertions but others are 1,000. The lower ones include some big names like Amphenol and Rean (Neutrik subsidiary).

I was offered some Amphenol ones and decided ask them and Rean about this "discrepancy". Rean did not reply but Amphenol said that their jacks were also good for 10K insertions despite the sales spec. So I took the plunge and I have to say they do not look as well made or finished as Cliff, Neutrik or Switchcraft. I would not trust them and will use them in some other non critical application.

Of course the unbranded ones could be anything and will be avoided in future. As my dad would have said "Don't spoil the ship for a ha'porth of tar". He started his adult life as a shipbuilder so it was apt.

This may explain why cheap, or sometime not so cheap amps have trouble with the input jacks.

I have two HH Amps with Cliff jacks. They were made in 1970/71 and gigged professionally for 25 years. All four input jacks are still silent and feel good although one of the switch contacts is slightly bent meaning no connection for the Active/Passive connection on one amp. Now for me 25 years for an electro mech part is OK.

So now to order some good parts and check out the latest circuit.

Edited February 11, 2015 by Chienmortbb

[Passinwind]

[quote name='Chienmortbb' timestamp='1423657235' post='2687466']
So now to order some good parts and check out the latest circuit.
[/quote]

I just did a bit of benchmark testing in RMAA and saw a few subtle things that may need massaging, but it looks pretty good all in all. These figures are with both the high pass and the parametric EQ engaged, neither of which change the measurements all that much when bypassed.

Edited February 18, 2015 by Passinwind

[Chienmortbb]

Two picture of the rear panel, the first witj the power switch in situ and the Powercon and one speakon resting in their respective holes but fromt mounted. The second shows the Powercon and Speakon mounted from the rear.

Of course they are not attached yet. I was favouring mounting from the front at the socket surrounds hide any imperfections in the metalwork. However the holes are so clean and Brest that if I have left enough Space behind, I will mount the sockets from the rear.

Incidentally I chose Powercon for the mains as it uses the same hole as the Speakons and the XLR and so was easier than cutting a rectangular hole for an IEC power socket. After a the trouble I had drilling and filing for the power switch it was definitely the right choice. Now I just have to make sure I never forget the mains lead.

Edited March 22, 2015 by Chienmortbb

[Chienmortbb]

So progress has been slow but progress has been made. The rear panel is now complete although I am waiting for a second Speakon/Jack combo socket to be delivered.

Despite my dislike of the use of Jack Sockets for speaker connection, the Combo sockets are rated at 15 amps (about 900 watts into 4 ohms). To get a Jack and a speakon in the same package, the length is about 6mm longer than a standard Speakon socket. The extra length is in front of the chassis ensuring that the length inside the chassis us the same. You can see the ewffwct of this on the second angled picture,

The graphics on the panel were designed on a computer and printed onto Waterslide Decal Paper. This works like the decals in an Airfix or Revell kit.

Edited March 18, 2015 by Chienmortbb

[Passinwind]

[quote name='Chienmortbb' timestamp='1426688085' post='2720796']
The graphics on the panel were designed on a computer and printed onto Waterslide Decal Paper. This works like the decals in an Airfix or Revell kit.
[/quote]

Looking really good. Are you going to have an EFX return pot and/or EFX bypass switch on the front panel?

[Chienmortbb]

I have enough space to do the pot/switch on either panel and the Decals are so thin that I can add the graphics to the rear later. I should have mentioned that there are 6 or 7 coats of acrylic lacquer over those decals to protect them.

I am so pleased with the decals that initially I will use them for the front panel too. Once I have finalised the design I may add an acrylic (Perspex/plexiglass) panel.

A couple of words on using the decals. I made few mistakes so I will add my advice for using them.

Once the decals start to dry, don't move them unless absolutely necessary, I did that on the speaker decal and if you look carefully you can see the problem.

Do not drill holes then attempt to line up the decals. It is really difficult. Put the decals on first. Leave them to dry for 24 hours. Cut the decals smaller than the panel. This allows the lacquer to seal the edge of the decal.

Spray 2-3 layers of lacquer before you drill holes. Once you have cleaned the holes apply 2-3 more coats of lacquer to seal the fresh edges.

Leave the lacquer for 24 hours before working on the panel again.

[Passinwind]

<p>[quote name='Chienmortbb' timestamp='1426691035' post='2720856']
I have enough space to do the pot/switch on either panel and the Decals are so thin that I can add the graphics to the rear later.[/quote]
Being able to do the graphics in stages is a great reason to go with your method. I've done inkjet printing on sticky-backed plastic sheets a few times, but those decals look a lot nicer.

[Chienmortbb]

[quote name='Passinwind' timestamp='1426692775' post='2720884']
<p>
Being able to do the graphics in stages is a great reason to go with your method. I've done inkjet printing on sticky-backed plastic sheets a few times, but those decals look a lot nicer.
[/quote] I have to say that I am very impressed with them. I got 5 A4 sheets ( three sheets leae and 2 sheets white) for £9 or approx $14 and so far have used half a sheet.

[Chienmortbb]

I am just wondering whether anyone is still following this other than Passinwind. I will keep posting but it would be nice to know.

[irvined]

Hi,

I am looking at your work, very impressed.

Keep posting.

Cheers,

Doug

[Chienmortbb]

Great I just did not want to waste anyone's time. I will be designing the front panel soon and may put a couple of designs up to guage opinion.

[sifi2112]

Think there are enough of us reading your build that don't think you're wasting our time & I for one don't ... Very interesting & hats off to you for doing this ... looking forward to see the end product.

I've built a few cabs & would love to build just a power amp into one but to be honest most of the amp techy stuff is way over my head.
I looked at the module you bought but even tho they say its 'plug n play' I don't see it but it is new to me.