Matchless Spitfire Questions

[mbratch]

I've had bad hiss/hum experiences with pre-amp tube names that start with the letters "EH"... :-/

I'm actually quite pleased with how far down I've taken the hum (versus hiss) on the Spitfire clone. I ended up tweaking the virtual center tap resistor balance on the heaters to get there.

[mbratch]

Oh I have one more Matchless Spitfire question...

Does anyone fine the Line out useful? It's pretty icky sounding (as one might expect since there's no speaker emulation of any kind on it).

[guitarmike2107]

yes, sorry , I was referencing the layout you linked to, it uses a resistor... too much confusion for me

[guitarmike2107]

I've had bad hiss/hum experiences with pre-amp tube names that start with the letters "EH"... :-/

I have just said that same thing somewhere else, I steer clear of them now

[Diablo]

The best mod I can recommend is to swap out that crossline master volume with the Larmar type - use a dual ganged 250 K pot, and remove the two 220K grid leak resistors for the output tubes. You can also add two 2.2M resistors from the wipers to ground - to get 220K when the pot is turned to max volume. At full volume, the circuit is identical to stock.The 250K pots do the job of the grid leaks. The crossline master sounded awful in my DC30 clone.

[cminor9]

I built a Spitfire about a year ago. It does have a bit of hiss when you turn the vol all the way up (the preamp vol, not the master). I built it stock according to this: http://www.diyguitarist.com/PDF_File...ireChassis.pdf I used metal film resistors. Comparably, my store bought fender deville has about the same amount of hiss when full up. Of course, being that this is a relatively low wattage amp, you'll usually run it harder ergo more hiss. No recording, sorry, but if I get some time in the next few days I'll make one. Have never played a real Matchless, but I have heard some models do have a little hiss.

It's a very bright amp. I wouldn't fuss with the cathode bypass cap. As an earlier post mentioned, you won't get any more bass upping the value of the cap from 25 to 50. I certainly wouldn't make mods to make the amp any brighter.

I didn't build with a line out.

As for the filter caps, I have seen it drawn with four or five filter caps. Mine has 32, 32, 22, 22 + a choke. It's got a really tight response, even when dimed. Totally different feel than a 5E3 or something like that.

Here is a pic of the chassis: 4_mostly_complete | Flickr - Photo Sharing! The lead dress might not look like much, but I actually took great care in crossing wires, spacing them, etc. I don't make ruler straight runs like old Hiwatts.

I used JJ power tubes. I wouldn't write off EH tubes. I *love* their 6v6 and have used their 12ax7s with good results.

I do not really care for the sound this amp with the preamp really hot and the master dialed down to bedroom levels. Then again, I don't care much for the sound of a hard driven preamp and a dialed down master. To me, that sounds as generic as every 12ax7 stompbox out there. Maybe Diablo's mod would help, but I hope you aren't looking for a bedroom amp. This amp is best with all knobs at 12 o'clock or higher, where you can use the guitar's vol for clean/dirty. Got it paired with a WGS Reaper and a Veteran 30 and it's LOUD. With a good hot set of humbuckers, this amp really screams.

[trem]

I've had bad hiss/hum experiences with pre-amp tube names that start with the letters "EH"... :-/

I'm actually quite pleased with how far down I've taken the hum (versus hiss) on the Spitfire clone. I ended up tweaking the virtual center tap resistor balance on the heaters to get there.

Is there a pot for this, or did you make a change to the resistors..?
Thanks

[mbratch]

Is there a pot for this, or did you make a change to the resistors..?
Thanks

I didn't have a pot handy at the time, so I grabbed a number of resistors from my resistor box in the range of about 470 to 1K ohms and tried each using an alligator clip in parallel with one of the 100 ohm resistors in the center tap (chosen by experimenting which one reduced the hum). The 470 in parallel with one of the 100 ohm resistors gave the least hum, so I just soldered it in. I will probably get a hum balance pot and put it in at some point. But right now the hum is quite minimal. You have to do some focused, close listening to hear it. It's bus buried by the moderate level of hiss.

[mbratch]

cminor9, I'll probably leave the circuit stock. I really like the tone of the amp. It seems to work well with either my strat or Hamer Artist (mahogany). I play live mostly, so I leave the master at maximum and I put the volume at about 3:00 and use the volume on the guitar to get semi-clean to a louder, dirtier lead tone. In this configuration, I plug into the "low" input jack.

This was a home-made amp someone else sold to me cheap, but it's a good build. I may, down the road, play with the circuit a bit just for fun. Maybe I'll find another use for the line-out jack.

Your amp looks great. The pre-amp seems nice and compact, almost like a PTP layout. And I dig the whole made from scratch vibe. I hope to build an amp from scratch some day...

At home, practicing, I've been playing the amp through the speakers in my 1969 Pro Reverb, which is a pair of original Oxfords. I have to say, the Spitfire makes the Oxfords sound awesome.

What kind of speakers to you use? I know a lot of people like greenbacks. But I've heard good things about Jenson MODs for this amp, too.

[guitarmike2107]

You can use a pot, fender used a pot in several of their amps, there have also been discussions about it at AX84 recently

Here’s one I sell, But you can get them at loads of places, If your in the states AES or Mojo are bound to have them
POTENTIOMETER 100OHM 3W "HUMDINGER" - MODULUS AMPLIFICATION

[mbratch]

You can use a pot, fender used a pot in several of their amps, there have also been discussions about it at AX84 recently

Here’s one I sell, But you can get them at loads of places, If your in the states AES or Mojo are bound to have them
POTENTIOMETER 100OHM 3W "HUMDINGER" - MODULUS AMPLIFICATION

Thanks, yeah I was planning on "upgrading" to a pot eventually.

[cminor9]

Warehouse Guitar Speakers. They have a good reputation for making Celestion clones and supposedly improving the designs. You can order them direct from Watch your Tone! | Warehouse Guitar Speaker.

I got a Reaper (which is like a beefed-up greenback) and a Veteran 30 (like a Vintage 30). That's a pretty tried and true combo (Dr Z uses that for his Z Best cab, I read somewhere that Matchless used a similar combo too) and it. sounds. amazing. I cannot say enough good things about those warehouse speakers. I A/B'ed it with a 1x12 cab with a Weber Blue Dog (another speaker I just love) and I have to admit, the WGS speakers sounded better. Not exactly a fair comparison, 2 speakers against 1. But still. Since I am not made of money, I didn't A/B them against the Celestions they clone. All I know is that I spent about $140 for a set of speakers that sound *great*.

Thanks for the kind words, I like the homemade vibe too. I do need to make nicer faceplates though. Got a silkscreen kit to make professional-grade faceplates, just need to make the dang thing. I forbade myself from building anything else until I get that done. We'll see how that goes.

[mbratch]

Ah right, I've read good things from users about WGS speakers. I may give them a go.

About the faceplate, there are lots of options. You could go silk screen, or even something hand painted could be cool. Or how about this? Maybe one could make a front panel out of an LCD screen then you can have the labels be whatever you like, when you like, and you can even have a background image.

[cminor9]

mbratch, as promised (though much later, sorry) I was able to record a sample of the spitfire build.

I recorded it with my iPhone, with the mic about 4-6" from the speaker. Started with a 5F2-a for reference, a 5E3, and then the spitfire. The 5F2-a is dead quiet, I added it for a frame of reference because any noise you hear there is ambient noise. The 5E3 has carbon comp resistors and is a bit hissy. The spitfire is the noisiest amp, by far. The volume knob (not the master) seems to impact the noise the most, so it's probably just some stray noise going into the first stage. All recordings were made with a guitar plugged with the volume all the way down (so you aren't hearing any pickup hum). This spitfire is also the loudest of them all, though, so a bit more noise is OK in my book. I know it's hard to compare this to yours, but maybe it'll help.

I have read conflicting information about Matchless amps. Some say they are extremely quiet, others have reported that they are a bit noisy. I'd imagine that since noise is due to so many variables, environmental factors probably contribute to that range of opinions.

Any questions, let me know.

[mbratch]

Hey that's great, cminor9. I found it very helpful.