Recommend Black Face Deluxe Reverb Kit

[TheTinMan]

cminor - it sounds like you've already made up your mind to a certain extent, but there ARE real, audible differences between cheap and decent quality components.

I don't especially care about measuring with anything other than my ears, but I can hear a big difference between cheap cables and decent cables. Frankly, I wasn't expecting to when I did A/B/C/D tests.

Speakers - everything else could be great and still sound terrible with a bad speaker or even the wrong speaker for a given application. Take a stock Blues Jr. as a prime example.

Cabinet - material, construction, open vs. closed, dimensions, baffle board mounting ALL make differences you can hear. You could use the best of everything else, put it in an MDF cube, and it will sound terrible.

Tubes - yes, you can hear differences but that doesn't mean you must have $250 Telefunkens. Cycle a handful of current production 12AX7s through a Tweed Champ and you'll find the ones you like (and don't like).

Output transformer - it can be "too good" as well as "cheap". I've got a 5F2-A build with a high quality OT from Dave Allen that's going to get pulled and replaced by the smaller, cheaper one that came with the "kit". Bigger & better makes too much bass and somehow the distortion isn't as sweet. IME output transformers may have the most mojo of any component. (Allen's OT will go in another build it's better suited to.)

Power transformer - 25 volts plus or minus on B+ can be heard in many amps. Way too big or way too small would be bad, but is there really value added from boutique here? Don't know. BTW no one should pay full retail for Mercury Magnetics. I like their product but sure won't pay the 1 unit prices!

You don't want anything mechanical to fail - pots, tube sockets, jacks, switchs - just aren't worth skimping on.

Caps & resistors - search the web and read on...

And then there's shipping costs. IMHO you're much better off if you can find maybe three suppliers you can count on for acceptable quality and good customer service to get everything. Finding the lowest price for every part will drive you crazy and cost you a fortune in shipping. Between Hoffman, AES, Mojo (Marsh actually) and Mouser, I can get virtually everything I need.

Hope this helps,

Chip

[cminor9]

TheTinMan, yeah, that's all pretty much how I feel about all the various parts. Some need to be good, some are just silly to overpay for. Speakers, cab design and materials, and tubes clearly need to be good and the right choice for whatever sound you are after

The original post mentioned MM transformers. I was just wondering (aloud) if anyone really found a way to justify overpriced transformers, cables, and caps. Sounds like a few folks think cables matter, but nobody has really spoken up on overpriced transformers or touted the virtues of those ridiculously overpriced "audiophile" caps. I guess that just kind of confirms what I already thought.

[MWJB]

MM transformers are not that expensive, they are overpriced for what they are though. Good quality fender style replacements like Hyboer & Lenco will do the job plenty good (standard caveat with all these aspects - unless there is something specific you personally are after).

Foil & oil caps - lack character, I've fitted them to amps & then taken them back out at the owners request - how much difference do they make though? Less difference than you'll hear from one cable to another! They were never fitted as stock to any classic production amp. Some claim to prefer the less coloured tone, others just read them off in a list of components as if they were reading qualifications from their resume, as if it makes them a better player! If you use regular priced OD or Mallory caps and your amp doesn't sound good, it's because of something you have done in the build NOT the caps.

I even use cheaper Euro metallised poly caps in my own amps & repairs where the customer isn't brand concious - sometimes you have to fit parts that give a customer peace of mind. Metal film resistors & square poly coupling caps in vintage rebuild? The customer won't thank you at resale time when the amp is picked apart on Ebay!

Speakers? Well, the one you like the sound of best is the one to use, price is the secondary consideration. Trouble is few get the opportunity to A/B test speakers in the same amp withiout having to stump up their hard earned first. I've spent $200+ on a speaker and found it money well spent, conversely I've spent $75 and felt I was robbed.

Central to all this is the importance of ear testing, listening is not a passive experience, you may not hear certain things until someone more experienced points them out.. then you can't get away from it & design it out of new builds etc. The more ear testing you do the better you get...memory for sound is generally very poor (unlike smell for instance, ever walked into a room and been mentally transported 20yrs back to school because of the smell of the floor polish etc?). At first, by the time you've heated up an iron removed the old part & installed the new, you often can't remember what the original part sounded like...eventually you get better at it - if there is a charcteristic that you don't like/want more of, you will recognise it after modding. Being able to rig up instant A/B tests is a good thing to do when starting out.

[Diablo]

OK, let's get back to building the Deluxe Reverb kit. My Mojo kit is on the way, and I did an inventory of rectifier tubes. I have:
5V4G - coke bottle
5V4GA
5U4G - coke bottle
5U4GB
5Y3G - coke bottle
5Y3GT

I understand that 5V4 is higher voltage than 5U4 which is higher voltage than 5Y3. Will they all work OK in the kit with a rebias?

For power tubes, I have:
6V6G - coke bottle
6V6GT
I assume these will work OK with a rebias?

I also have some very old 6L6 coke bottles - I assume those won't work because they'll draw too much power?

Opinions please.

[Bruce / Mission Amps]

Diablo - I know that you wanted one-stop shopping, but if that kit uses "tag board" with eyelets you might want to consider getting a pre-made board made out of Garrolite from Watts Tube Audio (turretboards.com). You can get an AB763 board made with either eyelets or turrets. I've had really good experience with them.

You did say you wanted the build to be "first class" and tagboard is not IMHO.

Chip

I agree with much of your other statements but I'm glad you said IMHO this last time because like mine, that's all that is, your opinion.
But I think you are 100% wrong about eyelet boards... and I have over 1,250 amps and kits out in the field to back that statement up.
Eyelet boards are wonderful.
When done properly, first class and much easier for novice builders to work with because it is very easy to remove and replace parts on them, unlike Turret boards, which IMHO, are a royal pain in the ass to work with when it comes to R and R'ing parts that have been installed on turrets the way most people try to do.
Now it is true that MOJO makes their own eyelet boards, as I do, but their downfall is, as many others, that there are some areas that require three, four or more wires, resistor or capacitor leads to be inserted in an 1/8" dia eyelet, who's actual inside dimension is not even 1/8"... and that makes it hard.
In those special cases I use larger brass eyelets in those spots so a builder doesn't suffer that difficulty!
A simple remedy, where it appears I am the only one who does take these things into consideration.

[Bruce / Mission Amps]

OK, let's get back to building the Deluxe Reverb kit. My Mojo kit is on the way, and I did an inventory of rectifier tubes. I have:
5V4G - coke bottle
5V4GA
5U4G - coke bottle
5U4GB
5Y3G - coke bottle
5Y3GT

I understand that 5V4 is higher voltage than 5U4 which is higher voltage than 5Y3. Will they all work OK in the kit with a rebias?

For power tubes, I have:
6V6G - coke bottle
6V6GT
I assume these will work OK with a rebias?

I also have some very old 6L6 coke bottles - I assume those won't work because they'll draw too much power?

Opinions please.

Personally I would build the amp first and use all the cheap tubes that came with it to get it up and running correctly!!
I would probably favor the 5U4GB in place of the others mentioned and if you have NOS 6V6s, I'd use those even though the 6V6EHs are actually quite good.
You normally would not ever use a 5Y3GT rectifier in a Deluxe Reverb.
The black face ones, with their 110ma PTs and lower B+, wound for 115vac to 120vac, would be using a GZ34/5AR4
The 5V4 is not a higher voltage tube then a 5U4GB. It is a lower current handling tube (125 to 150ma max) and it has a different impedance then the others so depending on the current load through your rectifier, the actual B+ voltage will vary greatly depending on what rectifier you use.
This would be OK in a DR... but I'd still consider the 5U4GB, unless MOJO says their PT is wound with period corrected secondaries and then you should use a GZ34/5AR4....
The 5U4GB is rated at an incredible 275ma to 500ma. Two of these in parallel could run a 100 watt amp all day long.
So even though it has a high impedance and will drop some voltage across itself when used, it can handle a boat load of B+ current.
The 6L6 coke bottles should work fine if you set the idle current of each so they are not running more then around 12-15 watts each, though the DR OT is wound for an impedance that better suits a pair of class AB1, fixed bias 6V6s.

[Diablo]

Thanks Bruce. Your advice about using the new cheap tubes makes sense for firing up a new amp build.

[TheTinMan]

I agree with much of your other statements but I'm glad you said IMHO this last time because like mine, that's all that is, your opinion.
But I think you are 100% wrong about eyelet boards... and I have over 1,250 amps and kits out in the field to back that statement up.
Eyelet boards are wonderful.
When done properly, first class and much easier for novice builders to work with because it is very easy to remove and replace parts on them, unlike Turret boards, which IMHO, are a royal pain in the ass to work with when it comes to R and R'ing parts that have been installed on turrets the way most people try to do.
Now it is true that MOJO makes their own eyelet boards, as I do, but their downfall is, as many others, that there are some areas that require three, four or more wires, resistor or capacitor leads to be inserted in an 1/8" dia eyelet, who's actual inside dimension is not even 1/8"... and that makes it hard.
In those special cases I use larger brass eyelets in those spots so a builder doesn't suffer that difficulty!
A simple remedy, where it appears I am the only one who does take these things into consideration.

Bruce - First off, your opinions should carry more weight than my "facts".

Obviously I wasn't clear in my earlier post. My point was that I prefer a solid G-10 or GP-03 board to tagboard, not turrets vs. eyelets. More robust construction without humidity problems. (Living in Virginia makes one worry about humidity ) Even so, Leo Fender made a crapload more amps using tagboard than all of us here put together will ever build!

Turrets vs. eyelets is purely personal preference, and I didn't even state mine. I did mention that turretboards.com makes boards with either turrets or eyelets despite the name.

Frankly, I'm coming to the conclusion that turrets require more planning in advance about what will be connected where. Sometimes it's better to have what seems like an "extra" turret (or two) just to avoid tying too many things to one point. Even so, you're right about it being hard sometimes to replace parts and tweak things with turret construction.

Your suggestion about using larger eyelets for potential problem spots is great!

Sorry I hit an obvious "hot button" for you.

Cheers,

Chip

[Diablo]

I'll have a good look at the board material that comes with the Mojo kit. I have G10 available at work, and can order up some eyelets or turrets to do a prettier job. I was thinking it should be pretty simple to use the board they supply as a template to make my duplicate board from G10.

I was even thinking about making up a duplicate chassis - we have a new water jet machine at work, press brake, and lots of galvanized steel sheet.

[Mandopicker]

Here is what my Mojo Board looks like...

Not sure if it is necessary to spend a lot of extra time making a new board for the Mojo kit. I found the existing board design and material to be as good as any.

* Though I have neglected the center screw to hold the board down. This is because I wanted to position it such that it does not effect the way the filtercap board sits under the dog house. My original fenders just used a sheet metal screw which effects how neatly the board sits on the chassis and I wanted to avoid this.

As a result, I have elivated the filtercaps to allow for the correct screw, but have been just too lazy to take the amp apart again to do it. The amp just sounds so good right now. When I run out of projects, I'll add the center board attachment screw.

Anyway...that's what is great about building an amp from a kit...like Burger King...you can have it your way.

Have fun!

[Bruce / Mission Amps]

Bruce - First off, your opinions should carry more weight than my "facts".

Sorry I hit an obvious "hot button" for you.

Cheers,

Chip

Ya know, I re read my comments and it did sound like I was pissy for some reason and I didn't mean it that way.
I must have misunderstood your comment but, you used the word eyelets with tag board so I assumed you meant standard rivlets and eyelet boards, as seen in thousands and thousands of amps made by Fender, Marshall and zillions of others over the years.
However, by using the term "tag board" did you mean just the insulation board itself, or the boards with riveted on loops, like old VOX amps had?
Those loops things are OK, but I find that the old ones break easily if mis-handled with the soldering iron, lead pull offs or yanking parts off with needle nose pliers.

In my mind, tag board is kind of a carboardy, fiber thing and insulation board, like the G10 or FR4, both being a totally different thing.
I use the G10 and FR4 black stuff, cut and bored with a big $$ Laser machine for my boards while MOJO and WeberVST is/was (maybe still do) use a vulcanized carboardy thing, probably shear cut, and I think they're machine punched.
I think both boards are fine for the low voltage stuff we do with guitar amps.

[Diablo]

The kit has arrived. First thing I want to do is to drill the cabinet for the chassis strap holes. I was thinking of laying the chassis on top of the cabinet and using the chassis as a drill guide. Is there a clever way to locate the chassis on top of the cabinet for this step? Or, does anyone have the dimensions of the setback from the front slant of the cabinet to the chassis faceplate?

[MWJB]

Turn the chassis upside down, put it on top of the cab. Use a straight edge against the baffle board edge (where the beading is, behind the grill cloth) & line the leading edge of the slant so that it lines up with the edge of the baffle board (should be flush when all is tight), then make sure chassis is centred with regards to width of cab. Use the chassis holes to make some transfer marks on the top of the cab for your mounting holes.

[TD_Madden]

I STILL don't get why that cab isn't predrilled..it's THEIR kit, after all!

[TheTinMan]

I STILL don't get why that cab isn't predrilled..it's THEIR kit, after all!

I agree that it would be nice in a perfect world...
Some people buy the cab to use with a different chassis and the cab is made in a factory. Stocking two sets of cabs, one with holes and one without, would be a pain. Having some guy/girl in the warehouse drilling holes in cabs just before packaging them would cost more and risk quality control.

Chip