Help troubleshooting a Princeton Reverb Build

[Dr Tony Balls]

Hi All,

I'm building an AA164 Princeton Reverb and having some issues with noise/shutoff at elevated volumes.  I'm building to Fender's schematic and using my own layout, modifed from Fender's.  Everything works and sounds good at lower volumes, it just goes south as you turn up.  Here's what I have going:

TESTING WITH FULL AMP: As you turn up the volume control,at some point a ragged distortion starts to happen, particularly with a higher input signal (i.e. as you dig into the strings harder).  If you turn it up even more this becomes a squeal/oscillation,  This is exacerbated by maxing out the treble control, i.e. it happens earlier if it is all the way up.

TESTING WITH REVERB DRIVER REMOVED:  At some point I decided to test it with the 12AT7 (V2) removed and got different results.  Now there was no oscillation, but if both the Treble and Volume controls are all the way up it goes silent.  I should mention that I am testing without the reverb pan connected.

Deviations from stock:

- 470K grid stopper to PI adeed, per Rob Robinette suggestion
- 6.8K resistor in tone stack replaced with 25K Mids pot
- LarMar master volume added
- shielded wires used for girds of V1

Here's the Fender schematic i'm using:  https://schematicheaven.net/fenderamps/princeton_rev_gz34_aa1164.pdf

And here's my layout, let me know if there are questions:



Anyone have ideas what could be the problem or where to look?  Im an experienced builder and the "amp goes quiet at full volume thing is completely new to me".  I'm guessing that i'm looking at multiple problems given that its different with the Reverb Driver installed?

THANKS FOR ANY INPUT.

[Esquirefreak]

You might have better luck getting good answers if you also include pics of your actual amp/build.

/Max

[Dr Tony Balls]

You might have better luck getting good answers if you also include pics of your actual amp/build.

/Max

You bet.  Sorry I figured maybe the description would trigger an experience similar to someone elses.

Board and control panel:







Board and tube sockets (the jack between V2 and V3 is for footswitch):







And the reverb transformer connections and send/receive RCA jacks are kinda hidden beneath the V2 socket:

[stratomaster]

LarMar on a bias vary amp, and no safety resistors, is gutsy.  The commonly used Alpha pots have poor wafer to wafer matching.  At minimum I'd want to see safety resistors (ideally you'd pick some that aid in matching the wafers to each other) and a cap (say 10μF @ 63-100v) at the bias side of the Intensity pot to ground (mind the polarity).

For troubleshooting your squeal just max out the MV, no changes needed--this isn't the immediate problem.  It sounds from your description like positive feedback.  I think the reverb driver issue is separate. Try disconnecting the NFB.  If this cures the squeal, swap primaries.  Then we can look at the reverb.

Based on recent experimentation with my personal 68 Custom Reverb I've got some thoughts on the Princeton and its reverb circuit we can discuss if/when the time comes.

Edit: Just saw your images.  If you're grounding though the pots you're going to need more purchase.  I've run into Dr Z amps with similar build, and end up replacing pots meant to ground to chassis with longer bushing versions and toothed washers to ensure continuity.  You may have poor ground connections throughout the amp--and this can lead to your oscillation/squeal too.

Aside from the oscillation, what is the noise floor like?

[Dr Tony Balls]

LarMar on a bias vary amp, and no safety resistors, is gutsy.  The commonly used Alpha pots have poor wafer to wafer matching.  At minimum I'd want to see safety resistors (ideally you'd pick some that aid in matching the wafers to each other) and a cap (say 10μF @ 63-100v) at the bias side of the Intensity pot to ground (mind the polarity).

For troubleshooting your squeal just max out the MV, no changes needed--this isn't the immediate problem.  It sounds from your description like positive feedback.  I think the reverb driver issue is separate. Try disconnecting the NFB.  If this cures the squeal, swap primaries.  Then we can look at the reverb.

Based on recent experimentation with my personal 68 Custom Reverb I've got some thoughts on the Princeton and its reverb circuit we can discuss if/when the time comes.

Edit: Just saw your images.  If you're grounding though the pots you're going to need more purchase.  I've run into Dr Z amps with similar build, and end up replacing pots meant to ground to chassis with longer bushing versions and toothed washers to ensure continuity.  You may have poor ground connections throughout the amp--and this can lead to your oscillation/squeal too.

Aside from the oscillation, what is the noise floor like?

LarMar....i'm aware re: safety resistors and will be adding them.

NFB....The way I generally build (to avoid loud surprises) is fire everything up without negative feedback first to confirm operation, THEN connect the NFB quickly to see if any change occurs. It did not in this case, but I will try without NFB and see what happens.

Pot grounding....The only things rounded to the pots are the tremolo speed limiting resistor (temporarily) and the resistor for the bias supply.  All preamp grounds are connected through the board to the chassis next to the input jacks.  All power grounds are connected to a PT bolt.

Noise floor....low.  very quiet, with no indicative hum.

[Dr Tony Balls]

Can confirm that the problem is the same with the NFB connection removed.

[Willabe]

It looks like on many of the components, you just put them through the hole and soldered them in place. That can cause problems as time goes on. The solder wont hold and the connection will go bad.

You should always make a mechanical bond, crimp/bend, 1st before you solder them in.

The other thing is, 1. The green 3rd safety wire on the power cord is supposed to have it's own bolted chassis connection, not a PT bolt, by it self, no other wires with it. 2. The PT bolts nut will loosen and you will lose your ground. Use a bolt through the chassis.

With ground chassis bolts, use a star lock washer on both sides of the chassis and double nut, so they lock against each other. A drop or 2 of lock tight is good too.     

[stratomaster]

Do you own a scope and dummy load? If so, then a parasitic/ultrasonic oscillation will be easy to find.

If not then if you have a listening amp probe you can trace the signal through the amp until the point where you lose audio.  That will help you hone in on the problem area.

[Dr Tony Balls]

Do you own a scope and dummy load? If so, then a parasitic/ultrasonic oscillation will be easy to find.

I do, and can certainly do that (gotta dig em out).  I havent yet because I dont know that will solve what i'm thinking is a two part problem.  The first part is that without the reverb driver/pan, i'm getting no oscillation but I am getting signal cutoff with the volume and treble control maxed out.  I feel like if I solve that problem then I can insert the reverb driver and address that problem, but maybe they could be the same thing?  I suppose I could probe with the scope and see where the signal is stopping....

[stratomaster]

You can also go strategically grounding the signal at the grids to see what's happening.

I have a suspicion the absence of the reverb driver is just sending the existing oscillation into ultrasonic territory.

Just out of curiosity, what is your added Mids pot set to when you get your squeal? 25k in place of the 6.8k is a significant increase in signal.

[Dr Tony Balls]

You can also go strategically grounding the signal at the grids to see what's happening.

I have a suspicion the absence of the reverb driver is just sending the existing oscillation into ultrasonic territory.

Just out of curiosity, what is your added Mids pot set to when you get your squeal? 25k in place of the 6.8k is a significant increase in signal.

I'll go the grid-grounding route till my signal gen determines if its gonna work or not...

WITH V2 INSERTED AND TURNED UP TO OSCILLATION:
Ground V1A - no change
Ground V1B - silent, no surprise as this is essentially turning the volume off
Ground V2A/B - silent
Ground V3A - silent, no surprise as this is essentially turning the reverb pot down
Ground V3B - muted but still squealing
Ground V4A - no change, tremolo oscillator
Ground V4B - muted further, but still squealing

[Dr Tony Balls]

OH and the mids pot is set to the middle, thereabouts, but changing it to either extreme doesnt eliminate the oscillation.

[Dr Tony Balls]

Alright looking at in on the scope with a sine wave, working backwards...

V2 REMOVED, TURNING UP THE VOLUME AND WATCHING THE WAVE AS THE OUTPUT SIGNAL CUTS OFF
Grid of 4B: Sine wave grows as volume is increased till it cuts out at the same time speaker output cuts off.
Grid of 3B: Same.
Plate of V1B: Same.
Grid of V1B: Same.
Plate of V1B: Sine wave does not cut out when speaker output cuts off.

So this tells me its gotta be in the tone stack/volume control somewhere.  I'll check my components there and try replacing pots to see if I get a change.

[Calboy]

I'm always suspicious of silver micas, MV's as well.
Has that board material been used before?
I got some of those boards a while ago and I was wondering if it works without issues.

[stratomaster]

I'm guessing this is V1A that doesn't show anything at the plate. Please confirm for clarity.

Plate of V1B: Same.
Grid of V1B: Same.
Plate of V1B: Sine wave does not cut out when speaker output cuts off.

That is a good start.  The utility of the scope is that it allows you to see what you can't hear.  When you lose audio, retrigger the scope.  The oscillation is likely to be well above 20kHz, so your scope set to trigger at 400-1000hz will miss it.

This will give us a proof positive confirmation of ultrasonic/parasitic oscillation. 

Once you can see it on your scope you can see if moving leads around alters/eliminates it.

You can also reinstall V2 and see what effect it is having on the oscillation that makes it audible.

Once you see the enemy you can better attack it.

Also the SM cap comment above is a good one.  If it's not lead dress/crosstalk or a wiring error I'd strongly suspect that cap. You can put your scope probes before and after the cap to see if that's the source.

[Dr Tony Balls]

Yes sorry, that's a typo.  It was the plate of V1A that showed no change.

I'm doing all these tests right now with V2 removed.  I'm just watching the signal on the scope with the treble knob all the way up, and turning up the volume, watching and listening to it grow and then eventually die out.  This happens with the scope on lug 3 of the volume pot, but not on the plate of V1A, so it HAS to be something in the tone stack, right?

I'm never had a problem with Silver Mica caps.  I dont have another non-SM 250pF cap on hand, but I tried replacing it with another SM 250pF cap and no change.  I also tried four 1nF film caps in series, and no change.

I'm testing with the master volume all the way up (speakers on an attenuator).  The problem persists whether the MV is UP or not, or if the attenuator is on or not.

The board material has been used successfully on four prior builds, so I dont think that's a suspect.

I tried chopsticking with the treble and volume all the way up (i.e. when the signal dies) and notice no change.

I've reflowed all my solder joints between V1A and V1B and no change.

I tried replacing the treble pot and not change.  Can try the volume next.

The ONLY thing that produces a change is plugging in to the low input, but I think that's just attenuating the signal enough where the change doesnt happen.

[Dr Tony Balls]

Replacing the volume pot makes no change.

I also tried removing V3 & V4, so testing with only V1 installed and i'm still seeing the signal cutoff at max volume when probing the plate of V1B.

[shooter]

i'm still seeing the signal cutoff at max volume when probing the plate of V1B.

cutoff as in the top or bottom clip, or signal vanishes??


measure VDC at the same place, what happens at "signal cutoff"

[stratomaster]

When the signal vanishes, are you triggering on the sine wave?  I'd recommend turning off all triggering to determine if the signal is vanishing or if it's being swamped by an oscillation above the threshold for hearing.  Change your amplitude and time scales to see if you can find any indication of a signal when your audio vanishes.

You can also dissect the tonestack with your scope. Put your test signal in and trace it from the first triode plate to the treble cap and through the slope resistor and on either side of all the caps in the tone stack and through the pots.  There's no need to guess and throw parts at it when you have a scope.  You should be able to see exactly where things go awry.

[Dr Tony Balls]

i'm still seeing the signal cutoff at max volume when probing the plate of V1B.

cutoff as in the top or bottom clip, or signal vanishes??


measure VDC at the same place, what happens at "signal cutoff"

The signal all but vanishes.

Voltages at V1 "before cutoff" and "after cutoff" are:

V1A, pin 1: 218.6 VDC (bc)..........219.4 VDC (ac)
V1A, pin 2: 0.41 VAC (bc)............0.41 VAC (ac)
V1A, pin 3: 1.63 VDC (bc)............1.66 VDC (ac)
V1B, pin 6: 221.5 VDC (bc)..........225.2 VDC (ac)
V1B, pin 7: 2.34 VAC (bc)............2.53 VAC (ac)
V1B, pin 8: 1.60 VDC (bc)............1.51 VDC (ac)

[Calboy]

What is the resistance of the volume control and treble control when the signal vanishes.  Don't modern pots have dead spots from 0-1 and 9-10? 

[Dr Tony Balls]

When the signal vanishes, are you triggering on the sine wave?  I'd recommend turning off all triggering to determine if the signal is vanishing or if it's being swamped by an oscillation above the threshold for hearing.  Change your amplitude and time scales to see if you can find any indication of a signal when your audio vanishes.

I tried turning off any auto-scaling and got slightly different results on the scope.

Here's V1A plate before and after turning up the volume past the "die-off point":

Before


After



And here's lug 3 of the Treble pot:

Before




So something is noticeably different on the other side of the 250pF cap.  I tried the scope on the other side of the slope resistor, as well as the other sides of the .1uF and .047uF caps and all three have results that match the first set of scope pics (V1A plate).

[shooter]

putting a scope "inside" a TS will cause un-intended consequences


what does V1B's plate look like now

[Dr Tony Balls]

what does V1B's plate look like now

The same as the latter two scope pics.

[shooter]

so this is v1B plate?

[Dr Tony Balls]

so this is v1B plate?

Yes, after the volume is turned up to the critical point.

[shooter]

how creative you wanna get? 


put the AT from rev in V1, scope V1A plate and V1B plate (Got 2 probes?)


if the results are basically the same as the AX;
temp out the TS and REV, see fancy schematic.  The coupler can be anything from .001uf to .1uf

[Dr Tony Balls]

how creative you wanna get? 


put the AT from rev in V1, scope V1A plate and V1B plate (Got 2 probes?)


if the results are basically the same as the AX;
temp out the TS and REV, see fancy schematic.  The coupler can be anything from .001uf to .1uf

I'll try these this morning.  I dont expect the AT to be able to recreate the problem because, as I said somewhere up there, the low gain input does recreate the problem.  Also at current i'm testing without V2-V4, just to avoid anything and everything else, PLUS im seeing the problem at the grid of V1B...so I dont suspect the REV bypass will do much, but will try it.

[stratomaster]

I think you're getting reverb bypass suggestions because of rare but documented cases of distortion caused by the bias point of the reverb driver that affects the overall sound. It's especially prevalent in Princeton Reverb ​circuits and even more so with a master volume.  The theory is that the other distortion happening in the absence of a master volume masks the reverb driver induced distortion.  Once you introduce the master volume the reverb driver distortion becomes more apparent. I believe there was a thread about it over at TAG.

I think what you're seeing is straight up oscillation and likely due to layout/crosstalk.  I think you would benefit from chopsticking the amp while you have the oscillation visible on the scope.  This will help target what actions (pressure, taps, moving wires, etc) at which points in the circuit make a difference to what you're seeing.

To ensure the health of the remainder of the amp you can simply interrupt the connection between treble and volume pot and put your signal generator directly onto the input leg of the volume pot.  You'll have to increase the amplitude of the input to make up for skipping the first triode, but that's easy. Then you will have completely insolated the first triode and tonestack without heroics.

[shooter]

it appears because of the "high gain" you're breaking into a parasitic oscillation.  once that's sorta confirmed, the typical culprits are lead dress where sensitive signals meet powerful signals, but since you don't have any "down-stream" signals, you're looking for sketchy parts, bad connections like, tube to socket, small value caps, flaky tubes


by bypassing the TS and removing the REV from the circuit, you've narrowed the search by 50%

[Dr Tony Balls]

I think you're getting reverb bypass suggestions because of rare but documented cases of distortion caused by the bias point of the reverb driver that affects the overall sound. It's especially prevalent in Princeton Reverb ​circuits and even more so with a master volume.  The theory is that the other distortion happening in the absence of a master volume masks the reverb driver induced distortion.  Once you introduce the master volume the reverb driver distortion becomes more apparent. I believe there was a thread about it over at TAG.

I think what you're seeing is straight up oscillation and likely due to layout/crosstalk.  I think you would benefit from chopsticking the amp while you have the oscillation visible on the scope.  This will help target what actions (pressure, taps, moving wires, etc) at which points in the circuit make a difference to what you're seeing.

To ensure the health of the remainder of the amp you can simply interrupt the connection between treble and volume pot and put your signal generator directly onto the input leg of the volume pot.  You'll have to increase the amplitude of the input to make up for skipping the first triode, but that's easy. Then you will have completely insolated the first triode and tonestack without heroics.

Right but with V2, V3, and V4 removed the reverb circuitry should be totally benign, no?  The Master Volume is also all the way up for all of this testing, so it looks the same as the standard bias resistors and, again, with V2-V4 removed the bias of the power tubes shouldnt matter at all unless i'm missing something.

it appears because of the "high gain" you're breaking into a parasitic oscillation.  once that's sorta confirmed, the typical culprits are lead dress where sensitive signals meet powerful signals, but since you don't have any "down-stream" signals, you're looking for sketchy parts, bad connections like, tube to socket, small value caps, flaky tubes


by bypassing the TS and removing the REV from the circuit, you've narrowed the search by 50%

Alright.....12AT7 the problem still occurs. 

Bypassing the TS and going from V1A plate > .1uF cap > lug 3 of volume pot solves the issue!  With the volume pot dimed i'm getting a good wave shape on either side of the inserted bypass cap.  I'm getting a much more distorted signal at the plate of V1B, however this is to be expected given i've removed the losses the tone stack provides.

However the question is what does this mean?  With the TS in the circuit I was only getting that distorted scope signal with the treble maxed out.....so maybe the relatively large value of .1uF is helping me out?  I tried it again but replaced the .1uF bypass cap with a 250pF one and sure enough the problem came back.  So something is happening where i'm getting signal distortion but only with bright signals?

[stratomaster]

Sounds like you just confirmed the problem is in the SM cap. Do you have anything else you can try temporarily?  470pf-0.001μF?

Failing that, would you buy willing to try a gridstopper at V1B? Say 10k-22k.

[Willabe]

Note all the || wires running together down on the chassis below the pots.

All those wires running || with each other under the pots, that's very bad lead dress. You have the pots upside down, lugs are normally on top, that would help get some of those || chassis wires away from each other. And some of those wires should probably be in twisted pairs. 

Board and control panel:

[Willabe]

There's a reason Fender twisted all the input jack wires together, TS wires together, the verb wires together and the trem wires together. And kept them away from other wires.

[Dr Tony Balls]

Sounds like you just confirmed the problem is in the SM cap. Do you have anything else you can try temporarily?  470pf-0.001μF?

Failing that, would you buy willing to try a gridstopper at V1B? Say 10k-22k.

Right, but the problem is not that it was SM because I tried a film equivalent (4x0.001uF in series) and got the same result.  I tried replacing the 250pF in the TS with a 470pF and a 0.001uF and got the same results.

I also tried replacing the cathode resistor and cap from V1A for fear that a bad part might be causing too much gain there, but no change.

I'm not against trying a grid stopper, but that shouldnt NEED a gird stopper....its a pretty tried and true design.

I'm about ready to just replace the entire tone stack with new parts and hope that solves things....

[shooter]

I'm about ready to just replace the entire tone stack with new parts and hope that solves things....

good call
while you're at it;

All those wires running || with each other under the pots, that's very bad lead dress. You have the pots upside down, lugs are normally on top, that would help get some of those || chassis wires away from each other. And some of those wires should probably be in twisted pairs.

[Willabe]

I'm not against trying a grid stopper, but that shouldnt NEED a gird stopper....its a pretty tried and true design.

Yes, but your layout and lead dress is not a tried and true design.

Layout and lead dress matter just as much or more that the circuit itself. We've seen it happen here many times, bad layout/bad lead dress caused major problems.

[Dr Tony Balls]

I'm about ready to just replace the entire tone stack with new parts and hope that solves things....

good call
while you're at it;

All those wires running || with each other under the pots, that's very bad lead dress. You have the pots upside down, lugs are normally on top, that would help get some of those || chassis wires away from each other. And some of those wires should probably be in twisted pairs.

Right but this isnt a lead dress issue or chopsticking would budge it a bit, which it hasnt.  Those are exclusively tone stack wires and remember that completely removing the tone stack and replacing it with a bypass cap was only effective when the cap was sufficiently large.  Replacing it with a 250pF bypass cap did nothing. 

[Dr Tony Balls]

Sounds like you just confirmed the problem is in the SM cap. Do you have anything else you can try temporarily?  470pf-0.001μF?

Failing that, would you buy willing to try a gridstopper at V1B? Say 10k-22k.

Tried an 18K grip stopper on V1B....no change.

[Willabe]

Right but this isnt a lead dress issue or chopsticking would budge it a bit, which it hasnt.  Those are exclusively tone stack wires

Those are not exclusively tone stack wires, there's other wires in there, looks like maybe verb and trem. It's clear to see in those pics. Wires going pots past the TS pots.

Sure it wouldn't budge chop sticking those wires because of the long || runs.

[Calboy]

I'm curious, what happens if the mid pot is grounded.

[Dr Tony Balls]

I'm curious, what happens if the mid pot is grounded.

If you turn it one all the way to one side it effectively is.  Basically instead of a static 6.8K to ground its variable from 25K to 0.  But even if I replace it entirely with a 6.8K as per the original schematic it behaves the same.

[stratomaster]

Sounds like you just confirmed the problem is in the SM cap. Do you have anything else you can try temporarily?  470pf-0.001μF?

Failing that, would you buy willing to try a gridstopper at V1B? Say 10k-22k.

Tried an 18K grip stopper on V1B....no change.

That was your golden ticket out of redoing lead dress.  Sluggo wins this round. I'd say it's time to buckle down and start shortening, twisting, and laying wires.

[shooter]

Right but this isnt a lead dress issue or chopsticking would budge it a bit, which it hasnt.

once you add in the PI and the PA, it might well budge it...

[Dr Tony Balls]

Right but this isnt a lead dress issue or chopsticking would budge it a bit, which it hasnt.

once you add in the PI and the PA, it might well budge it...

Oh of course, but that's a downstream issue.  Right now i'm just trying to get it so that the basic amp, with no reverb and trem, is able to function at all ends of the tone/volume spectrum, which its not.  With the treble maxed out the volume cannot be maxed out or a distortion is introduced.  Through the speakers this sounds like it is cutting out, but on the scope it is visible starting at the grid of V1B, as shown in the pics.  Bypassing the tone stack alleviates this this, provided the bypass cap is of sufficient size.  Reintroducing the tone stack and adding a grid stopper at V1B seems to help the problem, but a bigger grid stopper than 18K will be needed to resolve it completely AND this amp should function fine without a grid stopper there.

I fully understand the importance of lead dress but at this point, this problem is emphatically NOT a lead dress issue.  The problem appears on the scope with V2, V3, and V4 removed.  The only wire leads from the pots that are anywhere close to each other are those related to the tone stack.

Before I completely replace the tone stack components, I think i'll try making something like this to sub in.  It just looks like a tone stack with the treble fixed all the way up and the bass in the middle.  It would give me an idea if replacing the stack fixes anything.

[Willabe]

The only wire leads from the pots that are anywhere close to each other are those related to the tone stack.

What are you talking about? We're not blind. 
It's very clear in your pictures that there's a mess of OTHER wires laying down underneath the pots. And you have the pots turned lugs down so the pots lugs are by those wires down on the chassis. If you had them turned up those lugs would be away from those wires and the pots cover shielding would help protect the pots inside track.   

I fully understand the importance of lead dress but at this point, this problem is emphatically NOT a lead dress issue.   

No, I don't think you do understand good lead dress practice. If you did you wouldn't have built that amp the way you have it. There's also more lead dress problems in the other pictures you posted.

[pdf64]

I've only just got around to reviewing the photos, sorry.
I think that the issue is that the output of the 2nd stage is too close to the input sockets.
The close proximity is causing excessive coupling, hey presto there's a feedback loop, with in and out signals in the same polarity.
A screening plate (metal, connected to the chassis) between the input sockets should help.

[Willabe]

A screening plate (metal, connected to the chassis) between the input sockets should help.

Where? Between the input jacks and what? The tag board?

To test this, unbolt the input jacks and hang them over the front of the chassis. Getting them away from the tag board and 2nd stage. If it stops it, then that's it.

[pdf64]

A screening plate (metal, connected to the chassis) between the input sockets should help.

Where? Between the input jacks and what? The tag board?

Sorry, yes, between the sockets and the circuit board.

To test this, unbolt the input jacks and hang them over the front of the chassis. Getting them away from the tag board and 2nd stage. If it stops it, then that's it.

Yes, that could prove the point.

[Dr Tony Balls]

I've only just got around to reviewing the photos, sorry.
I think that the issue is that the output of the 2nd stage is too close to the input sockets.
The close proximity is causing excessive coupling, hey presto there's a feedback loop, with in and out signals in the same polarity.
A screening plate (metal, connected to the chassis) between the input sockets should help.

BINGO!!!!  I put some shielding tape on a piece of card stock, grounded via an alligator clip, and put it between the jacks and the board and that solved the distortion on the scope.  I was able to pull it out and watch the distortion reappear.  A million thanks to you and everyone that was helpful providing a sounding board for problem solving ideas!