Blackheart Little Giant head blown.

[Duffy]

Possibly someone knows what happened or has had a similar instance of what follows.

I was playing my Little Giant at mid volume last night when it stopped producing sound and the red light went out.

An inspection this morning revealed that the fuse at the power cord input had blown, two amp fuse.

Opened the back and the EL84 has black flash residue on the inside of the tube glass at the site of the little rectangular openings in the tube plates. This appears to be burn marks from the tube blowing out catastrophically.

Remedy: a brand new Sovtek EL84 and fuse installation blew out immediately upon powering up the amp.

Condition: the amp is blowing the fuse immediately upon power up.



Plan of action: Tomorrow I am going to pull the amp chasis out of the head and closely inspect it for obvious hot spots, bare wire shorts, broken wire ground outs, burnt components, etc. I may possibly isolate an obvious short or other problem that will be easy to fix.

Help or ideas are definitely wanted. Anybody have this happen to their Little Giant?

What does this sound like; and does it sound like I will be able to isolate the problem and take corrective action?

I will take it apart tomorrow hopefully, and take some pictures of anything that looks suspecious.

I will not have this amp repaired by a pro tech because it cost only 139 US, and I'm not going to pay more than it cost to fix it.

Being a fairly simple amp design I'm hopeful that I will be able to identify an obvious problem that is not expensive to correct.

I'll keep you posted.

The good side: I got out my brand new, new style Epiphone Valve Junior head and rigged it up to my Epi So. Cal. cabinet that the Blackheart had been driving. Pure beauty. Ibanez ART300, "Swamp Water" plugged straight into the VJ produces incrediblely beautiful tone and goes into overdrive very nicely a little past half way open. Then I plugged in the Fender Am. Std. strat and it replicated the beautiful tone, similarly to the ART300, producing tones far superior to the more complicated blackheart.

I had relegated the VJ to placeholding status. I forgot how great it sounds and it certainly sounds fantastic. It is staying in my amp wall, regardless of what happens to the Little Giant.

I plugged a Boss tremolo pedal and an overdrive OD-3 pedal, along with my new Digitech Hardwire reverb pedal in between the guitar and the VJ, much to my delight. Awesome sounds coming out of this rig now. Very awesome.

So my bedside set up is real good for now: the newly hooked up VJ rig with the four by twelve cabinet plugged into one guitar, and my Delta Blues plugged into another guitar with a Bad Monkey in between it and the guitar.

This provides me with all the charm necessary to quickly put me and my fiance asleep with the guitar laying across my chest, eagerly awaiting to be reignited for yet another sleepy rock and roll.

[oldguy]

I hear ya..... I plugged the old modded V.Jr. into my 4x12 Sunday. Ran my Agile LP and then my Agile AS1000 semi hollow through my pedalboard, which includes DVM's original ZYS (actually the second one he ever built, I believe. He kept the first one for himself!), and it sounds great still to this day. Cranked it wide open, and let the tubes do their thing...... pure sonic bliss.

[jim p]

You could post over at Sewatt.com and see if anyone there has a response to your problem. If you are going to get in there with a volt meter you may want to make a light bulb current limiter to help you trouble shoot the problem. If the power tube did go soft and draw high current it could have changed the value of the cathode bias resistor from excessive power dissipation. The resistor would usually increase in value so a new tube would draw low current but maybe it went the other way or the cathode bypass cap could have shorted that would cause high current from near zero bias on the tube.

[kiteman]

Wow Duffy, I'm really surprised that the amp blew. They're supposed to be overbuilt and really heavy duty at that but I don't know about the OT though. Sounds like the OT shorted, just my guess though.

Hope you get 'er back on the road.

[Duffy]

It is a cool amp and especially cool looking. I'm going to look inside and see if anything looks obvious.
Paying someone to fix it doesn't seem cost effective considering it was only 139 to begin with.

Maybe there is a service bulletin out on these or something. It is definitely out of warranty.

Maybe I can fix it or have it fixed inexpensively, otherwise it is not worth it.

[marnold]

Sounds like a job for Tung or DVM!

[duhvoodooman]

I really don't consider myself qualified to start giving amp troubleshooting advice (pedals, yes....amps, no). But I have put out an all points alert for Dr. Tung! I'm sure he'll drop by forthwith....

[tunghaichuan]

It is hard to diagnose these types of problems over the internet, so posting pictures would be a big help.

Before poking around inside the chassis, you want to make sure you drain the filter caps, you can get a nasty shock if you don't. The easiest way is to leave the amp on and unplug it. Play through it until the sound dies out. Then let it sit for a while.

It could be a lot of things, so post some hi res photos of the PCBs and anything that looks like it might be toasted.

[duhvoodooman]

It is hard to diagnose these types of problems over the internet, so posting pictures would be a big help.
:thwap I should have known enough to have posted that comment myself! Over at the BYOC Forums (http://www.buildyourownclone.com/board/), photos are the first thing we forum mods ask for. And like we always say, make 'em "big, well-lit, well-focused closeups"....

[tunghaichuan]

Forgot to add:

The Blackhearts use the lead-free RoHS solder, so they can be difficult to work on. The PCB is double sided and there are joints on both sides of the board on some of the components, so that can make it a challenge to work on them as well. In addition, if you use too much heat, the traces will lift so watch out for that.

I've been meaning to open my amps up and do some mods, but after hearing a few horror stories about working on those amps, I've been kind of reluctant.

When you're looking inside the amp, look for any burned components, black or carbon deposits or any components with discoloration.

[Tig]

When you're looking inside the amp, look for any burned components, black or carbon deposits or any components with discoloration.

Also look for any components that are not "normal" shaped or appear "bloated".
I haven't actively T/S'ed component level boards since the 80's and 90's (you wouldn't believe how crude and ancient the systems at NASA used to be!), but I still remember a few things, kinda', maybe...

[jim p]

They have the schematic in the FAQ section over at SEwatt.com the amp has a bleeder resistor in the power supply so the caps should be discharged by it. If the pentode/ triode switch shorted to chassis it would cause a problem so it would be one thing to look for. The cathode bypass cap for the EL84 is 50 volts so not so sure it could have overvoltaged and shorted but you never know. If it comes to needing to replace the output transformer you have a lot of choices that could lead to better tone. Musical power supplies OT8 or OT10, a couple over at Triode Electronics to choose from, a 15 watt model at Ted Weber some as low as 19 bucks without shipping.

[Duffy]

Almost opened it up today.

Tomorrow I may open it up and take some pictures with my Nikon DSLR after I try to identify possible culprits.

The only other indication of a problem prior to the blow out was a few days before the blow out when the red power up light failed to come on when powering up. After minimal switching back and forth on the wattage toggle it came on and stayed on in each instance. This may be linked to the short or wiring problem. Never before had the light not come on when powering up.

The replacement Epiphone Valve Junior, new style, sounds so much better than the Blackheart that I am not putting the Blackheart back in the amp wall if it gets fixed. I will use it as a portable, stand alone unit with my other cab.

The Epi VJ sounds incredible with a pedal line up in front of it; overdrive OD-3, Digitech Hardwire reverb, and Boss tremolo. Using one or more of the effect pedals, or none at all, the VJ sounds incredible with sss single coil strats as well as high quality humbucker guitars. I'm going to use the VJ a lot because it is great and should get used, as such. I hope I don't have a reliability problem with it that even comes close to the Blackheart's record. That Blackheart has only a few hours on it, never abused.

Possibly opening it up will reveal a simple problem causing the blow outs. That would be nice. The Blackheart is such a simple amp to begin with I wasn't expecting problems any time soon.

Now that I'm a bit paranoid I'm hoping that the new style VJ's have an outstanding reliability record, and that it will stand up to heavy use, because I am definitely going to use it heavily, as one of my main bedside amps, to see if it holds up really well.

If it doesn't hold up either, I have a Peavey JSX Mini Colossal that I will use as the head for the cab and see how that stands up. The attenuator on the Mini Colossal is okay, but it definitely sucks tone when turned down significantly. I like the tone with the attenuator wide open.

I wonder how that cheap Kustom 99 dollar one knob five watt head sounds and holds up? Maybe I should consider an Egnater fifteen watt Tweaker or that twenty watt Ibanez tube screamer tube head.

Anything known about these? Might as well check them out while I investigate the problem with my Blackheart.

Tools and camera later today. That is if I can tear myself away from playing the VJ So. Cal. strat and HP Signature EXP superstrat HB connection - this is very fun and doesn't look or feel like work.

I will try to get on this and get some pictures up along with a couple new guitars I have been reticent in posting.

[kiteman]

I have that cheap Kustom 99 dollar one knob five watt head. :)

I haven't been using it but it's because it's too loud. Yea, a 5 watter that puts out like a 15 watter. Sounds good though.

[Duffy]

Additional info.

I took the amp apart and looked it over real good. Three more fuses inside, side by side, all good. No burn marks on the board or anywhere else. No swollen caps or resistors, etc. No evidence of any burn out.

I'm going to try to get some more small three mm fuses that go into the little door under the power cord and try plugging it into a different jack. It has been blowing this fuse IMMEDIATELY upon plugging in the amp, so there is no way I can use my digital multimeter to trace the current to a possible culprit, unless I can get it to stay on; and if it stays on I'm checking to see if it outputs to the cabinet and produces sound.

Very strange that this power cord fuse is blowing right there at the input point of the power cord. No evidence of messed up wires or burned components at the power cord input point - all wires going from it look good. Very strange.

Today I'm going to try to get some fuses - two amp three mm mini buss type cylindrical fuses, hard to find.



Anyone have any ideas what this could be?

Everything looks pristine inside the head chassis. Just blowing that fuse at the input point for the detachable power cord. Tried switching cords and immediately blew that fuse too.

I plugged in my Epi new style V Jr head and hooked it up to the same cabinet. Worked great, for a few minutes then the volume faded fairly quickly and came back in after a while then faded again.

Much checking it out to now avail until I finally noticed a couple days into checking it out, that there is an opaque white two piece coupling buss fuse container between the wires coming out of the inside of the amp and going to the power supply, a very short distance. This white fuse container was cock eye'd, I thought it was something else; it was not straight and rigid like a usual fuse holder.

Close examination revealed that the two locking tabs on the male cylinder that inserts into the basket female fuse holder receptacle were broke off, how I don't know.

This loose, unlocked fuse holder was allowing the cylindrical glass fuse to make intermittent contact inside the holder, resulting in the fading in and out of the amp as I played, much to my confusion.

Well, I finally figured it out and taped it shut with electrical tape, ineffectively I must note becasue the heat must have loosened the adhesive on the electrical tape and the fuse holder slipped apart again. Last night I fixied it semi permanently with duck tape strips that hold the fuse holder together way better. The wires at this point are so short that replacing the fuse holder would be difficult to do correctly unless I added wire, which I'm not hot on doing. I will see how the improvised solution holds up.

Just tried two slow blow fuses on the Blackheart - both blew immediately and I heard a slight buzz coming from the area of the transformer type large black box'y type thing on top of the amp chassis across from the Power Supply. The one that says 4, 8, and 16 ohms on it. This must be the component that allows you to switch impedance when you plug into the various impedance jacks; the wires from the speaker out jacks go into it. A slight fizz and then nothing. I didn't even see the power light come on. Very confusing.

How does an amateur fix something like this? The Crate engineer told me I could probably figure out what the problem is and fix it myself. I can't do this without help, especially since I can't check where my power halts in my circuit. If I had power in the circuit I could isolate the component causing the problem.

I think the power supply is shorted and that's why none of the secondary fuses are blowing.

The on off switch says On/On on the top and bottom of the case by the spade connectors and is just like the 3/5 watt power switch, exactly - same part number and exact appearance. Just two more wires attached to it. Seems like it should say on and off. It is definitely not obvious what this switch is but it looks pristine.

I may have found two hot solder spots on the pcb board where two wires attach saying they are "B" ac taps or something like that. Possibly these feed the impedance transformer or whatever the box is I heard fizz shortly.

Any insight is appreciated if any of this rings a bell.

[kiteman]

I suspect the power supply transformer, most likely on the primary side.

[tunghaichuan]

I suspect the power supply transformer, most likely on the primary side.

That's what I suspect, too. If your amp is blowing fuses on the IEC connector, then something on the primary side of the PT is shorted, most likely.

[jim p]

The transformer that was buzzing was the one with a 4, 8 and 16 ohm label on it? If so that is your output transformer I would think and not your power supply transformer. I think in a previous post you said you had to toggle the pentode / triode switch to get the amp to work so if the switch went bad and was shorting to chassis that would short the plate supply and draw high current through the output transformer causing the buzz. You can try removing fuse 1 and fuse 2 inside of the amp then replace the line fuse and see if the amp blows fuses then. If the line fuse does not blow then you have a short in the plate supply to ground, maybe at the pentode triode switch.

[Duffy]

Jim P-

Email me if you can. I would be willing to take you up on that offer to help me out on fixing this amp. It is in perfect shape, outwardly. Just can't figure out what is wrong with it and don't have the expertise to identify and correct the problem on my own. A repair shop would be more expensive than a new amp.

I'd like to save this one. This job is beyond my abilities.

Email me and let me know if you still want to help out. I will be responsible for all incurances.

Thanks for the offer.

[jim p]

If you click on the name of the person posting a menu should appear with a link to send an e-mail. So you should be able to contact me that way. I also sent you an e-mail with my e-mail address.

[Duffy]

Your name on the fret has the email and private message drop down options disabled. Didn't know if you knew that. On mine they show up.

[jim p]

Thanks I checked the box so I can receive e-mail now.

[jim p]

If the power supply transformer has a bad primary Ted Weber has one for the stand alone reverb that has enough current capability for 25 bucks without shipping. On the output transformer there are some replacements that are also approx 25 bucks without shipping. The lower price ones will not have all the taps as far as 4, 8 and 16 ohms. Just looked into it because over at Sewatt someone posted about having there primary go bad on the power transformer.

[Duffy]

On the output transformer I only need 8 and 16 ohm outputs. I could get away with a 16 ohm only if I had to, both my cabs are 16 ohms but some amps have 8 ohm speaker inputs.

I will look into the shipping and get the show on the road.

An onboard reverb mod would be really cool if a good one is possible.

I need to get a pickup boost pedal or a treble boost pedal. Do these boost pedals mess up your preamp if you overdrive them too much? Thought I read that they could have a harmful effect on the amp if the level was turned up too far.

Thanks for the info.

[jim p]

Well if you will need an output transformer with 16 ohms the OT8SE or the OT10SE (see here http://musicalpowersupplies.com/2.html ) would work. I have not used either one but I would get the OT10 bigger is usually better for bass response. But you may not need one anyway. On the reverb there are sound clips of the Belton digi reverb here http://www.thefret.net/showthread.php?t=9379&page=21 post #388. If I still have all the parts and PCB it would be approx 50 bucks to add it. The main issue would be the location of the reverb level pot on the VJ amps I have played it safe and installed them on the back panel. On the overdrive not sure you will harm the tube using one you would need to cause a high control grid current to do that. You could have blocking distortion if the output of the box is capactively coupled with the high input impedance of the amp. That is where the Fender style high and low impedance inputs would come in handy. You could make a low impedance jack to plug the box into then plug that into the amp or modify the overdrive box maybe.

Just going through the posts at Sewatt there is this output transformer at Triode Electronics http://www.triodeelectronics.com/40-18031.html that everyone is happy with.

[ZMAN]

He Duff don't get me wrong. I have been reading this thread and I still can't get my head around these little 5 watt amps. 138 in amp dollars is a set of tubes for a good 25 watter. I would think that these are disposable after the warranty is up. When I see numbers like 50 for this and more for that I see you wasting money for little gain. I know you are trying to find an easy fix to the problem but how much workmanship and parts can be put into a 140 dollar amp?
Not to say that I haven't wasted money on gear, but I would cut my losses and scrap it!

[jim p]

The amplifier costs 200 bucks at MF new. If you replace an output transformer it should upgrade the tone of the amp for approx 30 bucks. The 50 to 60 bucks is to add reverb to the amplifier. If the power supply transformer is bad the one at Ted Webber to replace it should cost approx 30 bucks. So to repair the amp the parts should be approx 30 bucks if you need to replace a transformer less if just a short, bad switch or bad cap.

[Eric]

I also feel that, in cases of modding, repair, etc., frequently the owner does those things as part of a learning experience.

I see your point, ZMAN, but the counterpoint is probably that getting advice on a message board is free, and if nothing else, this is helping bolster Duff's knowledge of this sort of thing.

[ZMAN]

I also feel that, in cases of modding, repair, etc., frequently the owner does those things as part of a learning experience.

I see your point, ZMAN, but the counterpoint is probably that getting advice on a message board is free, and if nothing else, this is helping bolster Duff's knowledge of this sort of thing.

I know what you are saying is true no doubt. My whole issue is the 5 watt thing. I think that these tube amps with such low wattage are being cranked to the max to get them to distort. I am pretty sure that if you took a 25 watt amp and ran it full out you would end up with problems pretty quickly as well. I have owned several small practice amps both SS and tube and I have had NO problems with them. Of course they are 15 watts.
I use a pedal to get the distortion.
I am a huge believer in help from message boards. They are an invaluable source of information and help. I guess I should not have said anthing that isn't really helping Duffs problem.
I have a pretty good relationship with Duff, and I was really trying to save him some money.

[Eric]

I am a huge believer in help from message boards. They are an invaluable source of information and help. I guess I should not have said anthing that isn't really helping Duffs problem.
I have a pretty good relationship with Duff, and I was really trying to save him some money.
I wasn't trying to say anything about your comment -- it was just to offer up a possible explanation.

I try to remind myself when I see people modding the life out of a piece of gear and sucking any resale value out of it that they are probably doing it to hone their skills, not to increase the value of the item. It's a different way of thinking.

[Duffy]

Zman - I am beginning to see your point. I'm thinking it over and I think it might be better to use the money to buy another Behringer GM110 thirty watt solid state amp, the copy of the Tech21.

My GM110 was stolen and sold by a relative I took in when no one else, apparently, would. Burned. That's when I had the Gibson SG and the Fender Hwy One stolen by the same character. You don't forget these things.

I collected on the insurance and got a USA Std strat new and a Michael Kelly Patriot Custom flammed cherry burst. Still haven't gotten a new Gibson.

So, you move on.

On the other hand repairing nice things, when efficient, is a good thing.

The challenge is to decide what is more interesting.

I know what you mean Eric, but this fix is beyond my capabilities to diagnose.
I'm fairly good within my limits, but don't like to chase a wild goose.

[ZMAN]

I wasn't trying to say anything about your comment -- it was just to offer up a possible explanation.

I try to remind myself when I see people modding the life out of a piece of gear and sucking any resale value out of it that they are probably doing it to hone their skills, not to increase the value of the item. It's a different way of thinking.
I understand completely and I am only saying that I usually only try to make a comment that can help. If I can't help I usually don't say anything.
Duff: I can't really comment on SS amps. I have only owned two. A Fender Champ 110, which was a great little practice amp, and my travelling amp a Vox Pathfinder 15R. My take on this would be to pick up a Blues Junior. I am not sure if you have one, but they are an excellent choice. 15 huge watts and you can set this baby up to get just about any tone you want.
In a really compact format, and as Duhvoodoman has shown, very moddable. IF that is a word LOL

[Duffy]

It's a word, Zman, and that would be a good amp, especially now that they are getting discounted.

[jim p]

I was re reading your early post about toggling the pentode/triode switch to get the power to come up and you could have a broken or shorted wire at the line power switch. The power switch and the triode/pentode switch are right next to each other so toggling that switch may have been enough to rattle the wire connected to the power switch. Also if the plate supply was shorted the power light would probably light because it is connected to the heater supply so a short on the plate supply would probably cause it to be dim at most but still light. Also the power switch is on the primary side (line) so a short there would only blow line fuses just like it is doing now. If the short is to chassis at the power switch if you ohmmeter at the line input on the back to chassis the two out side prongs of the IEC connector (three prong AC connector on back panel) should be open with the power switch in either the on or off position. You will need a good fuse in the line fuse holder when you test this.


If you were going to replace the head a new head out is the VHT Special 6 http://www.vhtamp.com/vht-special.html the head is 180 bucks on e-bay the combo 200 bucks.

[jim p]

Just to add to the story I have Duffy’s amp and the problem was a short inside of the transformer one of the 275 volt taps was shorting to the center tap. It was poor assembly on manufacture. I cleaned out the carbon due to arcing, moved the tap away from the windings and added high voltage RTV and the transformer is now fine. I had to use the TV repairman trick of using a light bulb in series to help find the short without going through a stack of fuses.

[duhvoodooman]

Nice that the transformer wasn't damaged by the shorting. Looks like the fuses were doing their job.... :thumbsup

[marnold]

That's really good news. Yet another fine display of Fretherness.

[Duffy]

I really appreciate Jim P's help and expertise in saving my Little Giant head. I couldn't have saved it myself. Sometimes when things seem hopeless there are people that appear, get involved, and turn things around. It isn't costing me much and shipping is low because Jim lives only a few hours from here. That Blackheart is a great looking and sounding little head. Super glad Jim could save it.

Crate pretty much "has a brand new bag" and it's the Blackheart line they are promoting.

I'm looking forward to getting it back in even better form than it was when I bought it. It is one of the original ones from when they first came out.

Thanks a lot for offering to help out Jim!

[jim p]

I sent an e-mail but just to make sure I thought I would post here the amp is on the way home. It should be dropped off today 10/12/10. If you hear a rattle that sounds like a loose screw when playing that is the EL84 it is microphonic so if you notice it you will need to replace it. The amp is cathode biased and was at 11 watts when I measured it so you can just plug a new one in. Also if you dial the VVR down just a bit it will make certain that the plate dissipation of the tube is less than 12 watts.

[Duffy]

I got my Blackheart head back from Jim P a couple days ago and have had some time to check it out.

I'm playing it thru an Epi one twelve cabinet for the V Jr, loaded with a 75 watt Eminence Lady Luck speaker.

The amp never sounded nearly this good. It sounds real real good.

Jim installed a replacement "Classic Tone", Magnetics Components, 15 watt single ended output transformer, no affln, in it. This new transformer has made an incredible improvement in the tone of my Blackheart Little Giant.

Jim also installed a VVR, variable voltage regulator, that is a dial that allows you to turn down the voltage to the power tube; enabling you to turn down the voltage and turn up the volume and get a great overdrive sound a very low volume levels. This is really nice to have and sounds very very good, even at four in the morning, especially in the dark where my senses seem to be more sensitive and I can groove on the sounds of my amps. Last night I played it with my new Agile AL 3100 in the dark and it sounded incredible, different, of course, from my new Egnater Tweaker head, but very great sounding indeed - as well as the Agile. I will definitely buy another Agile.

These repairs, mods, and shipping costs were very modest and Jim was able to save my otherwise perfect, non-workable Blackheart that was in pure mint condition.

I'm glad I made the modest investment in having the amp fixed and thank Jim P for figuring it out and coming up with some great modifications and improvements to the already very good amp.

This amp is really nice now.

Some of you other guys might want to consider getting the "Classic Tone", Magnetic Components, no affln, transformer installed in your Blackheart. Definitely worth the ten or so dollar very modest cost. I also installed a new Groove Tube EL84 power tube, #6 and that may also have improved the sound as well.

Many thanks to Jim P.

[kiteman]

I'm glad you got your baby back and better than ever. :dance

I'm glad My Handsome Devil has been a terrific amp and I was surprised that yours went down. I guess it was all in a manufacturing defect even though they were supposed to be overbuilt. That's the reason I bought mine.

EDIT: oh yea, kudos to Jim P. :dude

[oldguy]

Yeah, Jim P.'s da man! (and a seriously nice Fretter to boot.):applause

[Duffy]

That Little Giant went down with just a flicker of the red light when I powered it up one day. Blew the fuse right away.

Sat there in perfect condition and there wasn't anything I could do with my level of ability, since I couldn't check anything without power to the amp and I didn't know which points to check for continuity and I didn't know what continuity levels to expect. It was beyond me.

The amp was in brand new condition with very few hours on it, mint. Relegating it to the junk heap wasn't what I wanted to see happen to it.

I really appreciate one of the fretters, Jim P. offering to help figure it out. It's an awesome amp and again this morning, about four AM I played it in the dark with more adjustment to the VVR and got some very nice tones out of it using first my Agile AL 3100, a great guitar with chunky neck, and not long ago with my Fender Nashville tele, stock thru my Bad Monkey and digital reverb to great effect. The Nashville really sounded great and clear with a little overdrive and reverb but still real clear sounding with the note separation and beautiful chords. All this at low volume, quite undisturbing and actually relaxing to Charity, my fiance; me playing in bed. I have the Tweaker and the Blackheart stacked next to my bed with a couple other amps and some nice homemade Pacific Redwood stained shelves. Each head is connected to a separate cabinet to eliminate the accidental chance of powering up one of them while not connected to a load. I also have my new Vox AC15c1 below my laptop shelf in front of my bedside amp peninsula.

So having a couple real low volume, quality sounding, amp heads next to the bed makes late night grooving a real pleasure.

[jim p]

It is good to here how well the amp turned out. It took me 2 to 3 hours to figure out what was wrong with the power transformer and with a little dissection and clean up it was as good as new. I was not certain how big of a difference the output transformer would make glad to here it is a big improvement. The stock transformers can be too small and low in inductance which will mean poor bass response. At a quick look the stock transformer and the ClassicTone looked to be about the same size but maybe the iron (higher permeability) and the amount of turns in the ClassicTone are better and more turns for higher inductance. The two transformers may be wound differently also but I did not check to see if a common bobbin or split bobbin was used on either one. For tone the manufacture can play with adding defects that are similar to the original transformers in say an old Champ, but being this is a 15 watt transformer on a 5 watt amp I don’t think that is happening here at least as far as core saturation. Regarding manufacturing the version 1 Valve Junior transformers were junk they should have had an air gap to prevent core saturation and they were interleaved E and I sections with no gap. I think some of your high priced transformers such as Mercury do design in defects such as core saturation at high current levels (SE) and unbalanced turns ratios on push pull transformers which should increase second harmonics near full power. Anyway you got a good deal on the labor cost figure I made about 50 cents an hour on the deal but I did it to help out and see how the amp was built and to see what went wrong so thanks.