# The Velvetone



## loudtubeamps (Feb 2, 2012)

On the bench today.... my first time with a Velvetone.
In for a make over.
All metal cabinet and "use with confidence"... cause' it's CSA approved. 

































*nonreverb *


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## greco (Jul 15, 2007)

Ironic thread!
I played through one of those several years ago ...right here in Kitchener.
It was owned by a friend.


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## Latole (Aug 11, 2020)

For safety, I hope this amp have a 3 prongs A/C cable.

I won't truss '60 area CSA


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## nonreverb (Sep 19, 2006)

I remember working on one of those a decade or more ago!


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## nonreverb (Sep 19, 2006)

Latole said:


> For safety, I hope this amp have a 3 prongs A/C cable.
> 
> I won't truss '60 area CSA


They all were 2 prong in the '60's. Both UL and CSA approved them as that era predates the advent and requirement for 3 prong appliances. Remember houses up to a certain date were all fitted with 2 prong outlets. There was a long period where house owners had to update their antiquated electrical wiring to the new standards. As for scary, they should be retrofitted with 3 prong but they're still isolated from the AC mains.
The truly scary ones are the voltage doublers and those with direct to mains tube rectifiers with no power(read: isolation) transformers that both UL and CSA approved back then. Those are seriously dangerous and I still get them in for repair from time to time.


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## Latole (Aug 11, 2020)

Yes, I knew that at that time there was no power wire with a gorund.
I was wondering if this amp had been modified because it is dangerous to use it without ground, There may be 60 to 120 volts present in the chassis.
Amps not isolated by power transformers, I have modified several with old transformers of electric razor plug or with two 120/24 volts inverted transformers.


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## Sneaky (Feb 14, 2006)

KEIL made some great sounding amps.


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## Frenchy99 (Oct 15, 2016)

I love these odd ones !


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## nonreverb (Sep 19, 2006)

Latole said:


> Yes, I knew that at that time there was no power wire with a gorund.
> I was wondering if this amp had been modified because it is dangerous to use it without ground, There may be 60 to 120 volts present in the chassis.
> Amps not isolated by power transformers, I have modified several with old transformers of electric razor plug or with two 120/24 volts inverted transformers.


Unless the death cap is shorted, it shouldn't be a problem.


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## Latole (Aug 11, 2020)

nonreverb said:


> Unless the death cap is shorted, it shouldn't be a problem.


It is not my experience.


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## nonreverb (Sep 19, 2006)

Latole said:


> It is not my experience.


Yes it could lethal if the death cap shorts but the zap can be from the neutral/hot being backwards due to non polariszd plugs and is low current and hence non lethal....thankfully.


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## loudtubeamps (Feb 2, 2012)

nonreverb said:


> Yes it could lethal if the death cap shorts but the zap can be from the neutral/hot being backwards due to non polariszd plugs and is low current and hence non lethal....thankfully.


No worries here Richard, this puppy doesn't have one.


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## nonreverb (Sep 19, 2006)

How's the housing tied to the amp Doug? Insane it's all metal....


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## Latole (Aug 11, 2020)

nonreverb said:


> Yes it could lethal if the death cap shorts but the zap can be from the neutral/hot being backwards due to non polariszd plugs and is low current and hence non lethal....thankfully.


 I talk about amp with no Power Transformer Like this harmony H-400


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## loudtubeamps (Feb 2, 2012)

nonreverb said:


> How's the housing tied to the amp Doug? Insane it's all metal....


Yup, insane to be sure Richard, hence the continuity pic. in my op.
The one thing that *would have* put it firmly into the #1 position for insane designs?
not having an isolation X-former!
In defence of CSA, I did fire up the amp, stick my tongue on the case while standing in a bucket of water, all good.
The chassis is fastened to the cab with 4 metal screws.
Alas this puppy is sick , almost no output with new tube sockets and tubes.
The secondary of the output transformer looks good...measures .5 ohm DCR.
I haven't had time to check primary yet.
B+ voltages are in the low 100's, just enough to make it bark.
A schematic would be speed things up a bit but nothing out there.
The chassis is factory stock / unmolested, the cabinet is in pretty good shape with only a few small patches of seared flesh that were easy to remove with a plastic spatula.


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## Latole (Aug 11, 2020)

Wich tubes this amp ? 50C5, 35W4 and.....
First thing to do is to check tubes
Second follow signal path with 'scope or AC voltmeter
*____*
To check if amp is safe to use
Voltmeter in AC scale
One probe to amp metal chassis, other to a good house ground, like wall outlet ground, you will read more the 60 volts AC

Same if you touch another well grounded amp. Or your friend guitar string when playing


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## nonreverb (Sep 19, 2006)

loudtubeamps said:


> Yup, insane to be sure Richard, hence the continuity pic. in my op.
> The one thing that would have put it firmly into the #1 position for insane designs?
> not having an isolation X-former!
> In defence of CSA, I did fire up the amp, stick my tongue on the case while standing in a bucket of water, all good.
> ...


Looks to have a power transformer Doug. What do you mean no isolation? No nevermind....I misread the post....carry on...time to keep quiet.


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## nonreverb (Sep 19, 2006)

Latole said:


> I talk about amp with no Power Transformer Like this harmony H-400
> View attachment 334099


Yes, that's what I was talking about in my previous post(s). Direct to tube rectifier from 120AC mains voltage. This and the diode voltage doubler circuit design.


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## loudtubeamps (Feb 2, 2012)

Latole said:


> Wich tubes this amp ? 50C5, 35W4 and.....
> First thing to do is to check tubes
> Second follow signal path with 'scope or AC voltmeter
> *____*
> ...


 As Wild Bill would say...."you are preaching to the choir!" 
Appreciate your input Latole, always something new to learn.
No worries, I've got it covered.


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## loudtubeamps (Feb 2, 2012)

Sorry for the obscure wording, I guess I should have said ......
The one thing that_* would have*_ put it firmly into the #1 position for insane designs?
if there was no isolation X-former!


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## greco (Jul 15, 2007)

loudtubeamps said:


> In defence of CSA, I did fire up the amp, stick my tongue on the case while standing in a bucket of water, all good.





loudtubeamps said:


> the cabinet is in pretty good shape with only a few small patches of seared flesh that were easy to remove with a plastic spatula.


Thanks for my laughs for the day!


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## Frenchy99 (Oct 15, 2016)

Are you going to swap out the input for 1/4 jacks and so forth ? 

Really love the look of it.


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## loudtubeamps (Feb 2, 2012)

Latole said:


> Wich tubes this amp ? 50C5, 35W4 and.....
> First thing to do is to check tubes
> Second follow signal path with 'scope or AC voltmeter
> *____*
> ...


Tube compliment: EF86 pre - EL84 output and 6X4 Rectifier.


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## greco (Jul 15, 2007)

loudtubeamps said:


> As Wild Bill would say...."you are preaching to the choir!"


Has anyone been in touch with Wild Bill recently?


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## loudtubeamps (Feb 2, 2012)

Frenchy99 said:


> Are you going to swap out the input for 1/4 jacks and so forth ?
> 
> Really love the look of it.


The old Amphenol mic. connectors? Bonus...they are adaptors, so 1/4" panel mount jacks are stock.


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## loudtubeamps (Feb 2, 2012)

greco said:


> Has anyone been in touch with Wild Bill recently?


Not in a long time, maybe Bill Gill @ Home - ElectroGlide Amplifiers
would know ! ( joke, sorry Mr. Gill )
Maybe if we revive a post about which tubes sound the best, he may chime in?


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## WCGill (Mar 27, 2009)

loudtubeamps said:


> Tube compliment: EF86 pre - EL84 output and 6X4 Rectifier.


These would be them!


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## nonreverb (Sep 19, 2006)

loudtubeamps said:


> Sorry for the obscure wording, I guess I should have said ......
> The one thing that_* would have*_ put it firmly into the #1 position for insane designs?
> if there was no isolation X-former!


Indeed...might as well have the hot AC line voltage in one hand the neutral in the other and a tongue operated power switch to light you up....


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## loudtubeamps (Feb 2, 2012)

nonreverb said:


> Indeed...might as well have the hot AC line voltage in one hand the neutral in the other and a tongue operated power switch to light you up....


 and to add insult to injury , spill a full bottle (better still) , a can of your favourite bevy all over the top and back of the amp.


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## Frenchy99 (Oct 15, 2016)

nonreverb said:


> Indeed...might as well have the hot AC line voltage in one hand the neutral in the other and a tongue operated power switch to light you up....


I do that every morning to wake up !


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## loudtubeamps (Feb 2, 2012)

Riddle me this.....a fun little test for those interested in troubleshooting. 
Things are looking up, the Velvetone is alive again.
Surprisingly clean and loud for a single ended 5 watt amp with a well balanced tone.
Update: after digging in , there is indeed a cap from the neutral a.c line to chassis ground.
The initial firing up (after replacing pre and output tube sockets and a full compliment of fresh tubes) yielded almost no output.
O.P. X -former dcr measurements and b + voltages looked so ??
Disclaimer: My weak spot, not totally familiar with all of the 6Bq5 variants.
I don't use them in my amp designs and don't see too many _*old*_ amps using 6bQ5's .
.

Quiz time: 2 issues found and repaired.
#1: This amp had never been touched, pin #1 on the 6Bq5 is the connection to grid.

#2: once #1 was corrected the output was back but quite distorted and the B+ was fluctuating quite a bit when hit with signal from the guitar.
A check with the multi meter on _*D.C.v*_ setting revealed the problem.


Any thoughts on what I discovered to complete the repairs? 
Happy Halloween


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## nonreverb (Sep 19, 2006)

loudtubeamps said:


> Riddle me this.....a fun little test for those interested in troubleshooting.
> The Velvetone is alive again.
> Surprisingly clean an loud for a single ended 5 watt amp with a well balanced tone.
> Update: after digging in , there is indeed a cap from the neutral a.c line to chassis ground.
> ...


Just curious, do you think it's worth checking for AC leakage from the power transformer? I ask because it can be a problem with the first generation (-3 series) power transformers in Hammond organs and this amp appears to be from the same era....although not the same manufacturer obviously.


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## loudtubeamps (Feb 2, 2012)

nonreverb said:


> Just curious, do you think it's worth checking for AC leakage from the power transformer? I ask because it can be a problem with the first generation power transformers in Hammond organs and this amp appears to be from the same era....although not the same manufacturer obviously.


Hi Richard..I didn't think of that.
As mentioned the amp seems to be good to go now but yeah, worth checking.
I'll let U know what I find.
Thanks for a good troubleshooting suggestion.


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## loudtubeamps (Feb 2, 2012)

Mains x former is healthy *nonreverb *


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## jb welder (Sep 14, 2010)

loudtubeamps said:


> Quiz time: 2 issues found and repaired.
> #1: This amp had never been touched, pin #1 on the 6Bq5 is the connection to grid.
> 
> #2: once #1 was corrected the output was back but quite distorted and the B+ was fluctuating quite a bit when hit with signal from the guitar.
> ...


Ok, I'll play but I'm a bit confused . 6BQ5, pin2 is grid, pin 1 N/C. 
So I take it you found the wire from previous stage going to pin1 and had to move it to pin2 ?
If so, it must have worked before, so is it possible it uses some other 6BQ5 variant that has grid at pin1 ?
Issue #2 was a leaky coupling cap from previous stage?


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## loudtubeamps (Feb 2, 2012)

Only one response eh'?
*jb welder*, you nailed it and your cheque is in the mail. 
The quirky thing about this quirky amp was the fact that pin 1 (6bq5) was being used .
From what I googled, back in the day the 6bq5' had pins 1 & 2 tied together, not anymore (obviously),I did not know this.




__





When Working on EL84/6BQ5 Tube Amps, You MUST know This about Pins One and Two! | Warehouse Guitar Speakers






wgsusa.com




and yes...the blocking cap between the EF86 and the 6bQ5 was passing about 12 volts dc.
Actually sounds very nice in it's simplicity.


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## Frenchy99 (Oct 15, 2016)

loudtubeamps said:


> From what I googled, back in the day the 6bq5' had pins 1 & 2 tied together, not anymore (obviously),I did not know this.


I certainly did not know this ! 



loudtubeamps said:


> *@jb welder*, you nailed it and your cheque is in the mail.


@jb welder I`m impressed !


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## jb welder (Sep 14, 2010)

Frenchy99 said:


> @jb welder[/USER] I`m impressed !


"I'm worth a million in prizes"


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## loudtubeamps (Feb 2, 2012)

I couldn't find any old data sheets that shows P1 & 2 tied. This one from 1959 with nada on P1.
I would like to see a spec sheet showing the pins tied.


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## nonreverb (Sep 19, 2006)

I'm now going to have to research this. There must be some documentation somewhere about it.


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## nonreverb (Sep 19, 2006)

loudtubeamps said:


> I couldn't find any old data sheets that shows P1 & 2 tied. This one from 1959 with nada on P1.
> I would like to see a spec sheet showing the pins tied.
> View attachment 334690


Bingo...although it's the 7189, it's essentially the same tube just higher spec...


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## loudtubeamps (Feb 2, 2012)

nonreverb said:


> Bingo...although it's the 7189, it's essentially the same tube just higher spec...
> View attachment 334705


Good sleuthing there Richard. (Y)
It still doesn't explain how this amp has '6Bq5' on it's chassis and P1 connected , p2 terminal was clean and had never seen solder.
The amp came in for repair sans tubes, would have been nice to see the 6bq5 that was in the amp at birth, I might have been holding 'the missing link' in the evolution of this tube.
The mystery continues....unless, the amp never worked? pin 1 was soldered up instead of p2 on a Friday afternoon , last one of the day.


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## loudtubeamps (Feb 2, 2012)

Anyone else have a good mystery repair they would like to share?


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## nonreverb (Sep 19, 2006)

loudtubeamps said:


> Good sleuthing there Richard. (Y)
> It still doesn't explain how this amp has '6Bq5' on it's chassis and P1 connected , p2 terminal was clean and had never seen solder.
> The amp came in for repair sans tubes, would have been nice to see the 6bq5 that was in the amp at birth, I might have been holding 'the missing link' in the evolution of this tube.
> The mystery continues....unless, the amp never worked? pin 1 was soldered up instead of p2 on a Friday afternoon 5 minutes before the end of the day.
> View attachment 334736


It kinda does in a round about way Doug. The 7189 is basically a higher power EL84 and is identical in every other way. The fact that the datasheet shows both variants is telling. I'm still on the hunt for an EL84 datasheet showing the same info...


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## Paul Running (Apr 12, 2020)

1961 Mullard data sheet notes pin 1 as an internal connection.


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## nonreverb (Sep 19, 2006)

Paul Running said:


> 1961 Mullard data sheet notes pin 1 as an internal connection.


It doesn't appear to Paul. I had looked at that one as well. Pinout still showes no connection for pins 1,6 and 8. I'll keep looking too.


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## loudtubeamps (Feb 2, 2012)




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## loudtubeamps (Feb 2, 2012)

Just about every tube ever made on this planet....Nada, I give up.




__





Frank's Electron tube Pages






www.tubedata.info


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## Paul Running (Apr 12, 2020)

loudtubeamps said:


> Just about every tube ever made on this planet....Nada, I give up.
> 
> 
> 
> ...










I give-up.


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