trinityamps.com

hi all,
fired up the 30 watt. Powered up o.k.
Few issues:

- EF86 channel only works. Noticed v1 and v2 does not light up. Would it be Broken heater wiring??
- get big popping sound every time I turn the rotary switch. Maybe got wrong type (make before break or break before make)
-full power plenty of volume. when switched to half power 15w, max volume is at bedroom levels. Used Niks layout for wiring - on comparison to schematic looks correct. Hmm
- also at half power the master volume sweeps loud to soft to loud when you turn it up??
any help is appreciated.

Gonna need some pics Daz. Post voltages of the suspect tubes

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

visiting my amp guru to drop back his variac. I'll see if he can help first.
The EF86 channel at full power sounds great, great mid gain sounds.
Just have to get the 1st channel working.

o.k I sorted out the 1/2 power switch and master volume issue. I had one of the pins of the power tubes wired to the wrong coupling cap.
the EF86 channel really is fantastic, quite a bit of gain on tap. It doesn't sound farty or fuzzy when cranked like the original I tried. Maybe it's the combination of NOS EF86 (miniwatt) , the trannies (niks) and different values on the tone switch I used. You need to open up the master volume for it to really sound good, and it sounds better at 30watts at lower volume than 15watt, but nonetheless it's not a bedroom amp at all. This thing is LOUD!

It seem like 1 st channel must either something not grounded or wired correctly. I've checked and compared to schematic and it all looks good. Might give it a rest and come back to it.

Hi daz,

How is the troubleshooting going?

Cheers,

Chris.

all great except no signal from clean channel.
Well it's not grounding as ef86 channel works and is connected to same grounding scheme under the board as clean channel.
I am getting large voltages thru pin1 of v1 and v2 300+v.
Dunno why it's all wired up right.

I'm in no major hurry - these things shouldn't be rushed.
Here are some pics, wiring alittle messy I'll tidy up when all well & good:

Yipee! got the clean channel working - think it might've been a cold or loose solder joint on one of the preamp tubes. No hum, quiet as a mouse.

Only issue is the EF86 tube - I used a miniwatt but find when I crank the gain to 12 o'clock and turn master about 10 o'clock it screams microphonic! only on the high input, low input o.k.


Sounds awesome - having built a spitfire before, the dc-30 clean side (30w lightning) is more dirty and gainy in a good way. the interactive tone controls are alittle bizare, have to get used to it but plenty of tones on hand.

I noticed switching b/w channels, you do get a slight volume imbalance b/w clean side & when you crank the gain on the ef86 dirty channel (gets louder). Be nice to be able to set volume level for each channel.

I used Nik's trannies and they really sound fantastic. As good as anything out there.
Awhile back I played a real dc-30 and it was more fuzzy/farty on the dirty channel.

After I let this one break in, I think I'll mod the clean channel to be alittle cleaner (increase 56k resistor) maybe tame the ef86 gain alittle.

mate I am one happy camper!!

Cool You must be stoked!

I can't wait for the layout and BoM!

Cheers,

Chris.

Congrats Daz, Let's put a wrap on that layout and get another one built. Looks like the Tone Monster may be willing to give it a go.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Definately, I'm ampless at the moment and keen as hell to give this a go!

Cheers,

Chris.

o.k I'll fix up the layout on the weekend and email to you stephen to host.

Think I'll tackle a badcat as my next project!

Daz .. great to hear of your success. As you know (from our offline emails), I've built a two channel Lightning with ef86 tube in the extra channel. I tweaked it a bit to get it right (ended up using AC15 ef86 preamp values, rather than those used in the DC30). It has heaps of gain on tap, but with my second build I've experienced the same problem that you mention above. In my case, I used a 1meg pot for the ef86 channel volume pot (not sure why I did this .. lol). I've changed this to 500k (like the old AC15's) and will test tonight to confirm whether it's "tamed" the gain a little (note: in my situation, microphonics kick in when the volume is past "8" and MV is over "4").

Regards


Barry marie

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Barry M

Thanks Barry I'd be interested in hearing your results. The stock dc-30 should be ideally be o.k. The real dc-30 I played exibited none of these microphonic issues at high gain. I'm thinking it may be the ef86 itself.

If you have different types of ef86 maybe give them a go and let us know if there's any difference.

What are you guys using for the rotary switch in the EF86 channel?

I used a 5e3 style tone stack (Richie's modded 5e3 stack from the 18watt forum), with a 0.01uf cap. I'm real happy with this, but might replace the tone pot pot with a push-pull type and add a 0.0047uf or 0.0022uf cap, as an tonal option.

Regards

Barry M

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Barry M

just a 1p12t rotary switch (make before break) rated for 250v 3 amp. It makes a loud popping noise when switching so I think I need a break before make rotary.

Brand name recommendations? Where are you finding these things?

Nik at Ceri@tone will sell you one. It doesn't pop when I switch. As soon as he posts his layout, you'll be able to build one sweet amp. I'd love to post it, but Il'l need to get Nik's permission.

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www.CelticAmplifiers.com

Not sure of brand name. alpha maybe? They are a fairly common item in any decent electronics store.

There's the rub, my town, our state's Capitol, no longer has a "decent electronics store". The last one shut down their counter and only does telephone inside sales to large clients now.

Did you notice if that switch in Nik's kit has one of those little keyed rings where you can pre-set the number of stops on the rotary switch? Like, if it's a six-position rotary switch, can you set it to stop at five, or three, or whatever desired number of clicks?

'Cause Nik was telling me that he was not presently able to find a rotary switch for another project, and it'd be nice to be able to come back and say "you can just use the switch from your DC30 kit".

You guys have places like mouser etc which pretty much stock everything. You should find what you need there online.